CH 220C

ORGANIC CHEMISTRY LABORATORY

Spring, 2015

Section Page
1. General Information 2
2. Safety Information 2
3. Attendance 3 Make-Up Policy 3
4. Laboratory Protocol 3 Assigned Reading 3 Pre-Lab Quizzes 3 Lab Notebook 5 Chemicals 5 Due Dates for Reports 5
5. Orientation 5 In-Lab Information 5 Library Information 5
6. Check-In 6
7. Grading Procedure 6
8. Policy on Cheating 7
9. TA Office Hours 8
10. Faculty Course CoordinatorS 8
11. Course Web Page 8
12. Hints to Minimize Frustration IN ORGANIC CHEMISTRY 8
13. Work Schedule 10 Lab Report Due Date Schedule 10 Experiments 10
14. Supplements 17 A. Extraction of Unknown 17 B. Recrystallization of Unknown Products 18 C. Methyl Benzoate 19 D. Synthesis of Luminol 20 E. Azo Violet 23
1. GENERAL INFORMATION

PRE- and CO-REQUISITES

Pre- and co-requisites for CH 220C listed in the Course Schedule. Important: Because the lecture and laboratory courses are co-requisites of each other, dropping one of them requires that you drop the other as well, unless the drop occurs during the final 2 laboratory periods of the term.

Pre- and co-requisites will be checked and students not meeting the requirements must drop the course.

REQUIRED or RECOMMENDED COURSE MATERIALS

A. Experimental Organic Chemistry, 5th edition, by J. C. Gilbert and S. F. Martin, Saunders College Publishing, 2010 (Required). You must use the one sold at the coop.

B. Lab Notebook: A “carbon copy” notebook with quadrille-ruled pages with page numbers. The recommended notebook will be sold by Student Affiliates of the American Chemical Society at the beginning of each term (Required).

C. Turnitin.com Access Code (also called the pincode)

D. One Combination Lock: This must be a sturdy combination lock. UT Chem locks are available at the University Co-op. You MUST have them for check-in. Otherwise you will not be allowed to check into the laboratory until you have obtained the required locks. See p. 7 or this document for information regarding your responsibility for your equipment (Required).

E. UT ID card: Bring your UT ID card to every laboratory session. It is needed to obtain items from the stockroom.

2. SAFETY INFORMATION **READ THE GENERAL SAFETY RULES ON THE WEBPAGE**

|If you are pregnant now or become pregnant during the semester, you must immediately consult with the coordinator about your eligibility to continue in this |
|course. |

CLOTHING

Street Clothes: Shorts or short skirts cannot be worn in the laboratory at any time, with or without a lab coat. Your shirt must at least have short sleeves and cover your torso, i.e., tank tops are not permitted.

Note: If you wear these to laboratory you will be sent home to change. On hot days you may wish to bring a pair of jeans or sweatpants to change into before entering the lab.

Shoes: Closed-toe shoes must be worn, i.e. sandals or clogs are not allowed.

SAFETY GOGGLES

The clear safety goggles provided by the department must be worn at all times in the lab. If your vision is corrected, wear your glasses under the clear safety goggles. Safety glasses are not permitted as substitutes for the goggles. Not wearing goggles in the laboratory may result in your expulsion for the remainder of the period.

LAB COATS

The blue lab coats provided by the department must be worn at all times in the lab. Wearing a lab coat does not excuse you from being properly dressed. Not wearing a lab coat will result in your being expulsion for the remainder of the period. The coat must buttoned all the way to the top and the sleeves need to be unrolled.

RADIO AND MP3 PLAYERS

Radios and MP3 players are not allowed in lab. This also includes CD players and tape players. JEWELRY

It is strongly recommended that you not wear rings, bracelets, or watches to the lab. Such items can trap chemicals next to your skin, thereby worsening the effects of burns or allergic reactions. Also NOTE that the solvents used in this course may permanently mar the synthetic materials contained in watchbands and crystals!

3. ATTENDANCE

LAB LECTURE

Attendance at the laboratory lecture before your regularly scheduled laboratory period is required. This lecture provides some of the general "How To's of Organic Chemistry", and helpful hints on performing the experiments. It also correlates the laboratory experiments with the topics being covered in the lecture section. Most of this information is not written down anywhere; the only way to get it is from the lecture. Material discussed in the laboratory Lecture is also one of the primary sources of material for the quizzes in the course.

LABORATORY

Attendance will be taken at all laboratory sessions. You will not receive credit for any experiment scheduled for a laboratory period for which you have an unexcused absence. If you have an excused absence, you must obtain a makeup permit before you will be permitted to work in any of the labs outside of your own regularly scheduled laboratory period.

In some cases, data will be collected by groups of two or more students. Zero credit will be given if you are not present or did not participate in the experimental work. You are NOT PERMITTED to use data collected by others in the group work if you are not present at the time the work is done unless given explicit permission to do so by Dr. Fjetland.

MAKE-UP POLICY

Makeup Only excused absences may be made-up. Excused absences are those that are beyond your control, such as major emergencies and illness. Written verification of an excuse must be submitted for all absences, e.g., a doctor's note). To be eligible for a make-up laboratory period, you must request a permit for the make-up from Dr. Fjetland within one week of the excused absence.

A specific make-up day will be established for each experiment and that is the only day upon which the make-up work may be performed. You must have a make-up permit and must be on time to be eligible for the make-up lab.

Excuses will not be granted for the following occurrences, among others: oversleeping, trips not connected with official University activities, the need to study for another class, conflict with an exam. It is your responsibility to register for a laboratory section that avoids recurring conflicts that are not of an emergency nature.

There will be no exceptions to this policy!

Make-up reports are due when stated by Dr Fjetland.

4. LABORATORY PROTOCOL

ASSIGNED READING

Prior to each laboratory lecture, you should read the assigned pages of your text or of any hand-out associated with the experiments you are to perform.

PRE-LAB QUIZZES

A pre-lab will be given at the beginning of wet lab. The questions will be based upon the procedure and the theory of the experiment. It is strongly recommended so that you can use it to study for the quizzes. If you miss the quiz, you miss it. There will be no makeup quizzes given.

LAB NOTEBOOK

The laboratory notebook is a critical record of your accomplishments in the laboratory so you should treat it accordingly by making careful and complete entries in it. Your lab notebook must be written in ink. If an error is made, draw a single line through the error and then continue. Note that the original pages in your laboratory notebook should never be removed; rather, turn in the carbon copies of these pages as directed. The pages should be sequentially numbered and your name should appear at the upper right-hand corner of each page. Leave the first 2 pages of the notebook blank for future use as a TABLE OF CONTENTS. This notebook is the last line of defense if there are any problems with grades, which means DON’T THROW IT OUT.

Note: All prelab and postlab write-ups are to be done by yourself. Data interpretation and analysis are your individual responsibility and must also be done by yourself. Otherwise, the actions of the cheating policy (see Section 8) are applicable.

There is only 1 format for the laboratory notebook consisting of the following:

LAB PREPARATION

There are two halves to the experiment. The first half is preparation. Lab preparation will consist of two parts. The first is the prelab questions that will need to be answered. The questions are located in the back of your textbook. You need to complete the assigned prelab questions before each experiment. The second part is the prelab report. The prelab report will consist of the following:

1. Heading: Use a new page of the notebook to start the entries for the experiment. Provide information that includes your name, the date, the title of the experiment, and a reference to the place in the laboratory textbook or other source where the procedure may be found. See page 7 of your laboratory textbook for an example.

2. Main Reaction(s) and Mechanism(s): Write a balanced equation giving the main reaction(s) for the conversion of the starting material(s) to product(s). If you are conducting a preparative type experiment, such as the synthesis of cyclohexene, the reaction that converts cyclohexanol to cyclohexene is given along with all the catalysts and conditions required (see page 10 of your textbook for an example). If you are conducting an investigative experiment where a reaction is being studied, such as the relative rates of bromination, the general reaction needs to be given (see page 523 of your textbook for an example).

3. Procedure: Reference the source and page of the procedure and then give a summary of what you will be doing that day. Also include any changes that have been made

4. Safety Analysis: Discuss the safety hazards of the experiment that you will be facing. These safety hazard include the chemical hazards, equipment hazards and reaction hazards. You will also need to discuss how you will be dealing with each hazard. Most of the hazards will be standard uses, such as working with a concentrated acid. The lab will have standard operating procedures (SOP) for these types located on the webpage. If it is a standard use, then you just need to cite the SOP for that situation. Also print out the SOP and bring it to the lab. You should also have printouts of the MSDS’s for each chemical you will be using that day.

POST LAB REPORT

The post lab report will consist of the following sections: (All sections are to be in your own words. Don’t copy anything!)

5. Introduction: Give a brief introduction to the experiment in which you clearly state the purpose(s) of the experiment. This should require no more than 5-8 sentences.

6. Data and Results: Any observations that you make during the experiment belong here. This includes things like the color of the solution when mixed, how the reaction proceeded and what happened when you added a reactant. This section also includes the observed melting point, weight, and percent yield of the product. You must also put any and all spectra, TLC or other type of data in this section.

7. Discussion and Conclusion: Discuss the theory behind the experiment performed and give a detailed mechanism of the reaction if one exists. Then write a conclusion stating whether or not the experiment demonstrated the principles and if not, why the data were inaccurate. The discussion and conclusion is to be submitted to Turnitin.com (see below for details).

8. Post-Lab Exercises: Assigned post-lab exercises for a particular experiment are to be answered in your lab notebook in this section. They need to be placed after the conclusion section.

CHEMICALS

All reagents should be in your laboratory prior to the start of the laboratory period. These reagents will be located in the reagent hood. Solvents will be located in the solvent hood.

DUE DATES FOR REPORTS

The Prelab Report (Parts 1-4) and Prelab Questions are to be completed before the beginning of the laboratory specified in the Work Schedule. The TA will check and grade it to make sure that you have completed the preliminary report. It is your responsibility to make sure that the TA has checked and signed your prelab report. If you haven’t completed the prelab report when you walk into lab, you will not be allowed in until it is completed, and you will be deducted 100 % credit. Then you must complete the lab in the time remaining when you have finished the prelab report. If you do not finish the lab, you will not be allowed to make it up.

The Post Lab Report is due as specified in the Work Schedule and consists of parts 5-8. Your TA will sign the data section of your notebook after you have completed the experiment. It is your responsibility to make sure that your TA has signed your data section.

All Post Lab Reports are to be turned in to your TA at the beginning of the wet laboratory on the due date. Anything turned in after that time will be graded as late. Late Final Reports will receive 50% credit up to one week late. After one week, no credit will be accorded for the report. The Post Lab Report must be turned in typed with the exception of the data. The typed report will be submitted to the Turn-It-In website to be checked and printed. The printed report will then be turned into your TA along with your data section. Information regarding Turn-It-In can be found on the webpage. Please ensure that you have printed the Turn-It-In report in the correct format, or it will not be accepted. Directions on how to print your report are on the webpage.

Make-up labs: All papers due at the missed laboratory period will be due at your next regularly scheduled laboratory period. Post lab reports for experiments completed in the make-up laboratory are due as directed by the instructor. The same penalties as given above for late submissions also apply here.

5. ORIENTATION

IN-LAB INFORMATION

On the first day of laboratory you will receive information from your TA on the various safety-related items in the room. It is important to know the location of these items as they may be needed in an emergency later on in the semester.

LIBRARY INFORMATION

There are a variety of sources in the Chemistry Library (WEL 2.132) that you may need to consult during this course. Some of the resources are listed below. The web address is as follows: http://www.lib.utexas.edu/chem/.

1. CRC Handbook of Chemistry and Physics

Located on the Handbook Table, in many editions. Find the table in the CRC called “Physical Constants of Organic Compounds,” and look up your compound by name. Remember that a particular compound may go by many different names, so check synonyms! Older CRCs are quite different from newer ones in the way they are indexed and arranged; if you don’t find your compound in one, try another edition. The newest editions have useful formula, synonym and structural formula indexes after the Table itself. Abbreviations used in the Table are defined at its beginning. Do not use the index in the back of the CRC to find compound information. The CRC Handbook is now available on the Web.

2. Merck Index

Also on the Handbook Table. This book contains information about common organic, inorganic, and biological substances, and has a Synonym Index in the back.

3. Sigma-Aldrich Library of Chemical Safety Data

Two large black volumes located on the Handbook Table. Look up your compound name or its molecular formula (if you know it) in the Index in the back of Vol. 2. The entry will provide a structural formula as well as some physical data and hazard information.

4. Reference Resource

A resource for finding references is the Web of Science link on the Mallet Library main web page. This will allow you to search many journal sources for a topic.

6. CHECK-IN

At the assigned laboratory period you will check into a drawer and hall locker that contain all your equipment. A copyof the Checklist is attached (see Section 14). Anything that is missing or broken can be replaced free of charge during the CHECK- IN period. After this time, you will be responsible for all equipment and glassware. At check-out, drawers and lockers will be checked by the TA for broken or missing items, which you must be replace. Be aware that you are responsible for the safe storage of your equipment. Lost or stolen glassware will be reported to the UT Police and investigated by them.

To replace broken glassware or equipment, go to the stockroom with your student ID and purchase the needed replacements. You will be sent a bill from the University for any such items. Be very careful with your ground-glass kits. Each kit has a total replacement value of $165.

You are required to check out of your drawer upon completing the semester or dropping the course (see below). A $25 penalty plus a charge for missing equipment will be assessed if you fail to check out.

7. GRADING PROCEDURE

GRADING SCALE

This laboratory course uses the +/- grading scale. This grading scale has the following distribution:

|Grade |GPA |Grade GPA Recommended % Range |
|A |4 |93-100% |
|A- |3.67 |90 - 92% |
|B+ |3.33 |88 - 90% |
|B |3 |82 - 88% |
|B- |2.67 |80 - 82% |
|C+ |2.33 |78 - 80% |
|C |2 |72 - 78% |
|C- |1.67 |70 - 72% |
|D+ |1.33 |68 - 70% |
|D |1 |62 - 68% |
|D- |0.67 |60 - 62% |
|F |0 |Below 60% |

FINAL GRADE DETERMINATION

Each laboratory section will be graded on an individual curve, and distributions will be posted periodically. TAs will be provided common guidelines for evaluation of reports. The final laboratory letter grade will be calculated as follows:

a. A class curve may be established, and a letter grade will be assigned based upon final total score. b. To earn a C- or better in the course you must complete all assigned work and turn in all required reports.

REGRADES AND CORRECTIONS

Once an assignment has been returned, you will have one week to get an error corrected. After the week has passed, no regrades or corrections will be made on that assignment. The only exception to this is the correction of an error in the entry of the grade on the computer or an error in addition.

POINT DISTRIBUTION

|What |Points |
|Prelab Questions |20 |
| | |
|Prelab Report |10 ea |
| Heading |1 |
| Reactions |1 |
| Procedure |4 |
| Safety |4 |
| | |
|Post Lab Report |120 ea |
| Introduction |10 |
| Data and Results |20 |
| Discussion and Conclusion |60 |
| Technique |10 |
| Post-Lab Exercises |20 |
| | |
|Quiz |50 |

8. POLICY ON CHEATING FOR THE DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY

The University of Texas at Austin expects honesty and integrity to be the ordinary way of life in all student activities. Plagiarism, or the use of another person’s statements without giving proper credit, is dishonest and is regarded as cheating. Although group study and projects are often appropriate, it is expected that individual assignments and examinations will be the private efforts of the particular student. A student detected cheating beyond any reasonable doubt in the preparation of any individual assignment is subject to disciplinary action. See the General Information Bulletin.

The following are considered examples of cheating:

1. Copying raw data for a laboratory without actually participating in acquisition of the raw data.

2. Inventing data.

3. Filling in parts of laboratory reports that require the raw data for calculations or interpretation before the data are collected.

4. Holding discussions so thorough that they result in identical laboratory reports, homework assignments, and computer programs.

5. Allowing anyone to copy any laboratory report, homework assignment, test, or computer program, either now or in the future.

6. Gaining access to, having in your possession at any time, or using old laboratory reports for any purpose. If you have questions regarding the format of any laboratory write-up, you should consult your TA or AI.

7. Gaining access to, having in your possession, using or distributing at any time grading rubrics.

PROPPER CITATION

To avoid plagiarism issues, it is best to never copy anything and to cite properly. For more information regarding proper citation, use the following links as resources

1. http://deanofstudents.utexas.edu/sjs/acadint_avoid_ack_conv.php

2. http://uwc.utexas.edu/

9. TA OFFICE HOURS

TAs will hold office hours in Welch 2.306 at times posted at this office, on the course bulletin board, or on the web page. Feel free to consult with any TA and to ask questions concerning either laboratory or lecture material.

It is Departmental policy that undergraduate students are not permitted in research laboratories. If you wish to consult your TA outside of his/her scheduled office hours, use e-mail and your TA will contact you.

10. FACULTY COURSE COORDINATOR

|Dr. Conrad Fjetland |
|Office: NHB 1.128 |
|Phone: 232-7676 |
|crfjetland@cm.utexas.edu |
|Office hours: M 2-3, Th 11-12 or by appointment |

11. COURSE WEB PAGE

A web page has been developed for the course. Among other things, it provides the course syllabus, a listing of office hours, and links to MSDS information and web pages, if any, for the various lecture sections associated with the lab sections. The URL is http://courses.cm.utexas.edu/cfjetland/organiclab/.

12. HINTS TO MINIMIZE FRUSTRATIONS IN ORGANIC CHEMISTRY

Organic chemistry is one of the most exciting and challenging courses you will encounter at UT-Austin. The course encompasses a broad range of topics including petrochemicals, polymers, pharmaceuticals, and life-sustaining biochemical processes. Organic chemistry can bring immense pleasure and numerous rewards. Yet it may also foster frustrations, most of which involve time constraints. You may often feel overwhelmed by the sheer volume of material to be learned and the amount of work accompanying the demands of the laboratory. These are legitimate concerns. Much information is indeed covered, and considerable time is required both in and out of the laboratory itself.

There tend to be two major gripes that students have concerning the lab:

A. Keeping a laboratory notebook and preparing for experiments require too much time.

Good science practices dictate that certain documentation be present in your laboratory book. Because we believe in teaching good science, this problem cannot be changed. With practice, you should become more efficient at preparing your laboratory book. A pointer: If you can’t find the necessary information (physical data, hazards) in a reasonable amount of time, don’t worry about it.

B. Students feel rushed during the laboratory period.

To a certain extent, this is true. Most organic experiments involve several steps and techniques, one or more of which is often laborious and time-consuming. This is the nature of the beast. Nonetheless, organic experiments can be fun, especially if you can minimize frustrations. Fortunately, we have more control over time constraints during lab. Handling these problems is merely a matter of time management--making the most efficient use of your time in lab. To that end, the following suggestions should prove helpful:

1. Come to laboratory prepared. This point can’t be overemphasized. People who know what they are doing before starting are far more efficient than people who must constantly refer back to a procedure to find out what they are going to do next. Advance preparation also lets you find any ambiguous points in the procedure. You can then ask to have these clarified during laboratory lecture.

2. Start the experiment as soon as possible. This is usually not a problem. But you should be aware that you don’t have time to stop for a soft drink or to chit-chat on the way to the lab, if it occurs immediately following the laboratory lecture.

3. Familiarize yourself with the location of frequently used chemicals and equipment in the lab. You will save time by not constantly having to ask where things are.

4. Make the most efficient use of “dead time.” Many organic experiments have a stirring or reflux period during which there is nothing to do but wait. This time should be used for cleaning glassware and getting chemicals and/or apparatus ready for the subsequent steps. If there are qualitative tests assigned, they may be performed during such periods. These tests should not be done before starting the main reaction.

5. Don’t presume that every reaction will work perfectly (or even at all). Often, these “tried and true” reactions fail to proceed the way the book describes. Even professional organic chemists with years of experience can’t get every reaction to work for them, despite the fact that the reaction may be cited extensively in the scientific literature.

6. Clean your glassware before you leave lab. Like your pots and pans at home, laboratory apparatus is far easier to clean just after it is used rather than a week later. You will then be ready to start the next week’s experiment without delay.

7. Remember that your TAs and AI are here to help you. If you have any problems or feel your frustration level rising, please don’t hesitate to talk to us. Here’s to a successful, enjoyable semester!
13. WORK SCHEDULE

LAB REPORT DUE DATE SCHEDULE*

|Report |Due |Report |Due |Report |Due |
|Distillation |Period 4 |Substitution |Period 8 |Luminol |Period 12 |
|Extraction |Period 6 |Grignard |Period 9 |Dehydrobromination |Period 12 |
|Stereochemistry |Period 6 |Aldol Condensation |Period 10 |EAS |Period 13 |
|Arenes |Period 7 |9-Fluorenone |Period 10 |Azo Violet |Period 13 |
|Stilbene |Period 7 |Methyl Benzoate |Period 11 | | |

* All reports are due at the beginning of the period. Be sure to Submit Post lab reports to Turn-It-In.

EXPERIMENTS

|REQUIRED PRE-LAB PREPARATION! Read about the techniques listed at the start of each experiment in preparation for working in the laboratory. |

|Period 1 |Lab Lecture: 1-22, 1-26, 1-27 |Wet Lab: 1-26, 1-27, 1-28, 1-29 |

|Due Today |
|Reading Assignments (due by lab lecture) |
|CH 1, Parts 1–11 of General Information in Syllabus |
|What Are We Doing Today? (In Wet Lab) |
|CHECK-IN |

|Period 2 |Lab Lecture: 1-29, 2-2, 2-3 |Wet Lab: 2-2, 2-3, 2-4, 2-5 |

|Due Today |
|Reading Assignments (due by lab lecture) |
|Secs. 2.14, 4.1-4.4, 6.1 and 6.4 |
| |
|PreLab Exercises |
|Secs 4.3 and 4.4 Simple and Fractional Distillation (pl 13-14) problems 1-11 |
|What Are We Doing Today? (In Wet Lab) |
|FRACTIONAL DISTILLATION AND GAS CHROMATOGRAPHY (Investigative) |
|(Procedure, p. 141-142, Procedure, GC, TBA)(Post Lab Questions: pp. 143-144, Problems 2,6,14 pp. 208-209, Problem 2) |
| |
|This is one report. You do not need a procedure for the GC in the pre-lab write-up |

Notes for Fractional Distillation

• You will be given an unknown mixture of two solvents from the table below.

|Solvent |Boiling Point (°C) |
|Acetone |56.5 |
|Methanol |64.7 |
|Hexane |68.8 |
|Cyclohexane |80.7 |
|Heptane |98.4 |
|Ethyl Benzene |136.2 |
|Toluene |110.6 |

• Set up the apparatus for the fractional distillation as pictured in Fig. 2.39, p. 59. Use 30-mL of the unknown mixture that is provided. Be sure to insulate your apparatus with cotton wrapped in aluminum foil. This insulation should include the stillpot as described in the laboratory lecture.

• Prior to performing the distillation, prepare a graph in your notebook for plotting the head temperature vs. the cumulative volume of distillate obtained. During the distillation, look for plateaus, collect three fractions, A, B and C, and record their respective volumes. Measure the amount of residual liquid in the distillation flask (if any) so that a % composition of distilled liquid can be calculated. Also record the boiling points of A and C.

Notes for Gas Chromatography

• Each person is to shoot fractions A, B and C. Your TA will shoot the original sample and provide the necessary data. Identify what you think are the correct solvents by their respective boiling points. Then shoot those two solvents on the GC to confirm that identity.

• Use the data from your traces to calculate the percent compositions of the original mixture and fractions A, B and C. Include these calculations in your Final Report. Record the results a table having the following form.

|Sample |Boiling range (°C) |Volume (mL) |% Composition |
|Fraction A | | | |
|Fraction B | | | |
|Fraction C | | | |
|Mixture | | | |

• In the “Conclusions” section of your final report, determine the percent composition of the unknown mixture of your sample as well as a class average. Talk about why the average should be more accurate.

|Period 3 |Lab Lecture: 2-5, 2-9, 2-10 |Wet Lab: 2-9, 2-10, 2-11, 2-12 |

|Due Today |
|Reading Assignments (due by lecture) |
|Secs. 2.21, 3.1-3.2, 5.1–5.3, Supplement A and Supplement B |
| |
|PreLab Exercises |
|Sec. 5.3 Acid and Base Extraction (pl 23-24) problems 1-7 |
|What Are We Doing Today? (in wet lab) |
|EXTRACTION AND RECRYSTALLIZATION: DAY 1 (Investigative) |
|(Procedure, extraction, miniscale Supplement A, Procedure, recrystallization, Supplement B) |
|(Product Analysis: MP, % Recovery) (Post Lab Questions: pp. 167-171, Problems 6,7,11) |

Notes for Extraction and Recrystallization

• Obtain 1 g of the unknown mixture that is a 1:1:1 ratio

• Before coming to lab, prepare a table in your notebook that has the headings and entries shown below.

| |Initial |Crude |Recovery (%) |MP Crude (°C) |Purified Amt. |Recovery (%) | |
|Compound |Amt. (g) |Amt (g) | | |(g) | |MP Purified (°C) |
|Acid | | | | | | | |
|Base | | | | | | | |
|Neutral | | | | | | | |

• For the recrystallizations in this experiment, recrystallize each crude sample in the appropriate solvent provided by the TA.

|Period 4 |Lecture: 2-12, 2-16, 2-17 |Wet Lab: 2-16, 2-17, 2-18, 2-19 |

|Due Today |
|Reading Assignment (due by lecture) |
|Secs. 2.7, 3.1, 7.1 and 7.3-7.5 |
| |
|PreLab Exercises |
|Sec. 3.2 Recrystallizing Impure Solids (pl 5-6) Problems 1-9 (except 8a and 8e) |
|Sec. 7.3 Isomerization of Dimethyl Maleate to Dimethyl Fumarate (pl 41-42) Problems 1-10 |
|Sec. 7.4 Properties of the enantiomers of Carvone (pl43-44) Problems 1,2 and 7-10 |
|What Are We Doing Today? (In wet lab) |
|EXTRACTION AND RECRYSTALLIZATION: DAY 2 |
| |
|(STEREOCHEMISTRY:ISOMERIZATION OF DIMETHYL MALEATE (Preparative) and ANALYSIS OF CARVONES (Investigative) (Procedure, miniscale, pp. 220-221, Procedure, p. |
|225-226 Part 1, Procedure, polarimetry, TBA) |
|(Product Analysis: MP, % Yield) (Post Lab Questions: pp. 222-223, Problems 1,4,8 pp. 226-227 Problem 5) |

Notes for Stereochemistry

• Use great care in handling the bromine solutions, as specified in the “Safety Alert!”.

• For the sample to be kept in the dark, wrap the tube in aluminum foil and leave it on the bench-top.

• Test the odor and determine the optical rotation of the carvone samples provided.

|Period 5 |Lecture: 2-19, 2-23, 2-24 |Wet Lab: 2-23, 2-24, 2-25, 2-26 |

|Due Today |
|Reading Assignment (due by lecture) |
|Secs. 9.1, 9.3, 10.1, 10.4 and 10.6 |
| |
|PreLab Exercises |
|Sec 9.3 Bromination:Selectivity of hydrogen atom actraction (pl51-52) Problems 1-10 |
|Sec 10.6 Bromination of E-Stilbene (pl 61-62) Problems 1-9 |
|What Are We Doing Today? (In wet lab) |
|ADDITION REACTIONS OF ALKENES: BROMINATION OF (E)-STILBENE (Preparative) |
|(Procedure, miniscale, pp. 377-378) (Product Analysis: % Yield, MP) (Post Lab Questions: p. 381-382, Problems 2,7,11) |
| |
|FREE-RADICAL CHAIN REACTIONS: BROMINATION OF ARENES (Investigative) |
|(Procedure, pp. 326-238) (Product Analysis: Rates of Reactivity) (Post Lab Questions: pp. 328-329, Problems 3,5,12) |
| |
|These are to be written as two separate reports. |

|Period 6 |Lab Lecture: 2-26, 3-2, 3-3 |Wet Lab: 3-2, 3-3, 3-4, 3-5 |

|Due Today |
|Reading Assignment (Due by lecture) |
|Secs. 14.1–14.4 |
| |
|Prelab Exercises |
|Sec 14.4 Preparation of 1-Bromobutane (pl 84-85) Problems 1-9 |
|What Are We Doing Today? (In wet lab) |
|NUCLEOPHILIC SUBSTITUTION: PREPARATION OF 1-BROMOBUTANE (Preparative) |
|(Procedure, miniscale, pp. 467-468) (Product Analysis: IR, % Yield, Halide Tests) |
|(Post Lab Questions: pp. 470-472, Problems 8,9,12) |
| |
|ALKYL HALIDE CLASSIFICATION TESTS (Investigative) |
|(Procedure, pp. 869-871) |
| |
|This is 1 report |

Notes for Substitution

• Note: Despite what it says in the textbook, the 1-bromobutane layer obtained during the work-up of the reaction mixture is not cloudy.

• Conduct the reaction at ½ scale.

Notes for Alkyl Halide Tests

• Prepare a table in your notebook that has the headings that follow. The results for each test that you perform on each compound are to be entered in this table.

|Compound |Sodium Iodide |Silver Nitrate |

• Perform the tests on your product and on the other compounds provided in the hood! Put all used and unused reagents in the waste bottle. Rinse your test tubes once with acetone and put the rinse liquid in the waste bottle. Then wash your glassware at the sink.

• In the “Conclusions” section of your Final Report, explain the reactivities of each compound in terms of its structure and suggest possible structures for products of any positive tests that you observed.

Notes for Next Week

• WASH ALL GLASSWARE NEEDED FOR PERIOD 7’S EXPERIMENT THIS WEEK SO THAT THEY HAVE A WEEK TO DRY.

|Period 7 |Lab Lecture: 3-5, 3-9, 3-10 |Wet Lab: 3-9, 3-10, 3-11, 3-12 |

|Due Today |
|Reading Assignments |
|Secs. 19.1–19.4 |
| |
|Prelab Exercises |
|None |
|What Are We Doing Today? |
|ORGANOMETALLIC REACTIONS DAY 1: PREPARATION OF BENZOIC ACID (Preparative) |
|(Procedures, miniscale, pp. 643-645, and pp. 655-656) (Product Analysis: IR, % Yield, MP) |
|(Post Lab Questions: pp 660-663, Problems 4,15,16,18) |

Notes for Grignard

• Lightly grease all glass joints.

• Plan to add 1 or 2 crystals of iodine, no more than that, prior to beginning to add 2-bromopentane to the magnesium. You will receive additional instructions for initiating the reaction from your AI.

• You will perform this reaction at ½ scale.

|Period 8 |Lab Lecture: 3-12, 3-23, 3-24 |Wet Lab: 3-23, 3-24, 3-25, 3-26 |

|Due Today |
|Reading Assignment (due by lecture) |
|Secs., 18.1 and 18.3 and 17.1, 17.2, 17.4 |
| |
|PreLab Exercises |
|Sec. 18.3 Synthesis of Trans-p-Anisalacetophenone (pl 124-125) Problems 1-7 |
|Sec. 17.4 Reduction of 9-Fluorenone (pl 114-115) Problems 1-8 |
|What Are We Doing Today? (In wet lab) |
|ALDOL CONDENSATION: PREPARATION OF TRANS-p-ANISALACETOPHENONE (Preparative) |
|(Procedure, microscale, pp. 620-621) (Product Analysis: IR, MP, % Yield) |
|(Post Lab Questions: pp. 622-623, Problems 1,3,6,8) |
| |
|REDUCTION OF CARBONYL COMPOUNDS: PREPARATION OF FLUORENOL (Preparative) |
|(Procedure, microscale, pp.583-584) (Product Analysis: IR, MP, % Yield) |
|(Post Lab Questions: pp. 584-585, Problems 2,4,8) |
| |
|These are to be written as two Separate Reports |

|Period 9 |Lab Lecture: 3-26, 3-30, 3-31 |Wet Lab: 3-30, 3-31, 4-1, 4-2 |

|Due Today |
|Reading Assignment (due by lecture) |
|Secs. 20.1,20.2, Supplement C |
| |
|PreLab Exercises |
|20.2 Preparation of Benzocaine (pl 136-137) Problems 1,2 and 5-9 |
|What Are We Doing Today? (In wet lab) |
|ESTERIFICATION: PREPARATION OF METHYL BENZOATE (Preparative) |
|(Procedure, miniscale, Supplement C) (Product Analysis: IR, % Yield) (Post Lab Questions: pp. 676-677, Problems 1,6,7) |

|Period 10 |Lab Lecture: 4-2, 4-6, 4-7 |Wet Lab: 4-6, 4-7, 4-8, 4-9 |

|Due Today |
|Reading Assignment (Due by lecture) |
|Secs. 11.1,11.2, 20.1 and Supplement D |
| |
|PreLab Exercises |
|Sec. 20.4 Preparation and Chemiluminescence of Luminol (pl 140-141) Problems 1-12 |
|Sec. 11.2 Dehydrobromination of Meso-Stilbene Dibromide (pl 69-70) Problems 1-10 |
|What Are We Doing Today? (In wet lab) |
|CHEMILUMINESCENCE: SYNTHESIS OF LUMINOL |
|(Procedure, Supplement D) (Product Anlysis: Did it Glow) |
|(Post Lab Questions: pp. 695-696, Problems Nonne) |
| |
|ALKYNE FORMATION: DEHYDROBROMINATION OF MESO-STILBENE DIBROMIDE(Preparative) |
|(Procedure, microscale, pp. 406-407) (Product Analysis: % Yield, MP) (Post Lab Questions: pp. 408-409, Problems 2,6,7) |
| |
|These are to written as two separate reports |

Notes for Dehydrobromination

• Use the meso-stilbene dibromide that you prepared from period 5. If you did not make enough, some will be provided.

|Period 11 |Lab Lecture: 4-9, 4-13, 4-14 |Wet Lab: 4-13, 4-14, 4-15, 4-16 |

|Due Today |
|Reading Assignment (due by lecture) |
|Secs. 15.1, 15.4 and 15.5 |
| |
|PreLab Exercises |
|Sec. 15.4 Nitration of Bromobenzene (pl 94-95) Problems 1, 2 and 4-11 |
|Sec. 15.5 Relative Rates of Electrophilic Aromatic Substitution (pl 100-101) Problems 1-10 |
|What Are We Doing Today? (In wet lab) |
|ELECTROPHILIC AROMATIC SUBSTITUTION: NITRATION OF BROMOBENZENE (Preparative) |
|(Procedure, microscale, pp.516-517) (Product Analysis:% Yield, MP) |
|(Post Lab Questions: pp. 519-520, Problems 1,5,8) |
| |
|ELECTROPHILIC AROMATIC SUBSTITUTION: RELATIVE RATES OF REACTION (Investigative) |
|(Procedure, pp. 525-526 (part A)) (Product Analysis: Relative rates of Reaction) |
|(Post Lab Questions: pp. 527-528, Problems 3,5,8) |
| |
|These are to be written as one Report |

Notes for Rates of Reaction

• Predict the order of reactivity before you come to lab and have that prediction in your notebook.

|Period 12 |Lab Lecture: 4-16, 4-20, 4-21 |Wet Lab: 4-20, 4-21, 4-22, 4-23 |

|Due Today |
|Reading Assignment (due by lecture) |
|Supplement E |
| |
|PreLab Exercises |
|None |
|What Are We Doing Today? (In wet lab) |
|PREPARATION OF A DYE: AZO VIOLET (Preparative) |
|(Procedure, Supplement E) (Product Analysis: Dyeing analysis, pH affect) |
|(Post Lab Questions: None) |

|Period 13 |Lab Lecture: 4-23, 4-27, 4-28 |Wet Lab: 4-27, 4-28, 4-29, 4-30 |

|Due Today |
|Reading Assignment (due by lecture) |
|None |
|What Are We Doing Today? (In wet lab) |
|CHECKOUT |

14. SUPPLEMENTS

A. Acid-Base Extraction (Miniscale)

To prepare for this experiment, study the detailed instructions for using a separatory funnel.

Obtain from your instructor a 1 g of the unknown mixture (it is 1:1:1). Using an Erlenmeyer flask, dissolve the mixture in about 20 mL of ethyl acetate. Transfer the solution to the separatory funnel and the extract it sequentially with three 10–mL portions of 6 M hydrochloric acid. Combine the three aqueous acidic layers from the extractions in an Erlenmeyer flask labeled “acidic extract.”

Extract the remaining organic layer in the separatory funnel with three 10 mL portions of 6 M NaOH. Combine the three aqueous basic layers from the extractions in an Erlenmeyer flask labeled “basic” extract.

Transfer the organic layer into an Erlenmeyer flask labeled “neutral” extract. Dry the sample with Na2SO4.

While the organic solution is drying, cool both of the aqueous extracts in an ice-water bath. Neutralize the “acidic extract” with 6 M sodium hydroxide and add a little excess base to make the solution distinctly basic to pH paper. Neutralize the “basic extract” with 6 M hydrochloric acid and add a little excess acid to make the solution distinctly acidic to pH paper. Upon neutralization, a precipitate should form in each flask.

Collect the precipitates separately by vacuum filtration. Wash each of the precipitated solids on the Büchner funnel with cold distilled water. Collect the filtrate and label them appropriately.

Separate the “organic solution” from the sodium sulfate by gravity filtration and remove the solvent by simple distillation. Discontinue the distillation when only a small amount of material remains in the distillation pot. Allow the pot to cool and then attach it to the water aspirator to remove the last small amount of the solvent. Be sure to have a clean Büchner flask as an aspirator trap. Gently swirl the liquid in the pot to expose a greater surface area and to facilitate vaporization. The pot can also be warmed mildly with the warmth of your hands.

Transfer the resulting solid residue to the third vial and allow it to air-dry in the same way.

After the samples have been dried, re-weigh each of the vials to obtain the weight of the crude solids, and determine the melting point of each of them. The reported melting points are given below.

Compounds MP (°C)

Acidic benzoic acid 122–123 2-methylbenzoic acid 103–105 2-chlorobenzoic acid 138–140 salicylic acid 158–160

Basic 4-nitroaniline 149–151 2-methyl-4-nitroaniline 131–133 3-nitroaniline 112–114

Neutral 9-fluorenone 82–85 anthracene 216–218 fluorene 114–116 phenanthrene 101–103

Continue the experiment as directed to determine a suitable recrystallization solvent for each solid obtained.
14. SUPPLEMENTS (CONT.)

B. Recrystallization of Acidic or Basic Products

Recrystallization as a purification technique involves the following:

Selecting an appropriate solvent.

The following criteria must be met for a solvent to be used in a recrystallization:

1. The compound should be soluble (approx. 1 g in 20 mL) in hot solvent, but insoluble in cold solvent.

2. The impurities present in the compound need to either be completely insoluble in the solvent or be completely soluble in the solvent (at all temperatures).

3. The solvent should be volatile enough that it can be easily removed from the crystals.

4. The boiling point of the solvent should be lower than the melting point of the crystals, otherwise the crystals could melt before they dissolve in the solvent and form an oil. This event is called “oiling out” of the solid, and makes the crystals much more difficult to isolate.

Dissolving the crystals.

Place the solid in a suitable container. Add a small volume of solvent and bring it to a boil. After the solvent starts boiling, add small amounts of fresh solvent until all of the solid dissolves. It is important that you use a minimum amount of solvent.

Forming the purified crystals.

Allow the hot solution to cool SLOWLY to room temperature. Cooling the solution too rapidly (by placing it in an ice-water bath) causes crystals to be formed too rapidly and may possibly lead to entrapment in the crystals not only of solvent but also of other impurities. If no crystals form after an appropriate amount of time, several measures can be taken. For example you may seed the solution by adding a crystal or two of the original compound. Also, you may use a glass rod to scratch the side of the container at the air-liquid interface. If all else fails, place the container in an ice-water bath.

Isolating the purified crystals.

Isolate the crystals obtained from the recrystallization by vacuum filtration using a Hirsch or Büchner funnel depending upon the volume of crystals obtained. Then rinse the purified crystals with a small amount of COLD solvent.

Drying the crystals.

The purified crystals are usually allowed to air-dry in a watch glass or a vial.

14. SUPPLEMENTS (CONT.)

C. Fischer Esterification: Synthesis of Methyl Benzoate

Esters are important functional groups that can be synthesized in a number of different ways. Many esters have pleasant odors and are often used in foods and perfumes. One method to synthesize and ester is by combining an alcohol and a carboxylic acid. The problem with this method is that the alcohol is not a strong enough nucleophile to attack the carbonyl carbon of the carboxylic acid. Fischer overcame this problem by adding a strong acid to the reaction, which protonates the carbonyl oxygen generating a better electrophile. Because each step in the mechanism is reversible, care must be taken to avoid reversing the reaction.

[pic]

We will be synthesizing methyl benzoate from methanol and the benzoic acid that we made previously. Methy l benzoate is commonly used in the perfume industry and the food industry as a flavor additive.

APPARATUS

A 100 mL round bottom flask, a condenser, a stirbar, an aluminum heating block and a hot plate.

PROCEDURE FOR THE FORMATION OF METHYL BENZOATE

Synthesis

Place 1.0 g of benzoic acid and 25 mL of methanol in a 100-mL round-bottomed flask, cool the mixture in ice, pour 1.5 mL of concentrated sulfuric acid slowly and carefully down the walls of the flask, and then swirl to mix the components. Attach a reflux condenser, add a one inch stir bar, and reflux the mixture gently for 1 hr. with the set-up shown.

Isolation and Purification

Cool the solution, decant it into a separatory funnel containing 25 mL of water, and rinse the flask with 25 mL of diethyl ether (Use wet ether found in a supply bottle in each hood). Add this ether to the separatory funnel, shake thoroughly, and drain off the water layer, which contains the sulfuric acid and the bulk of the methanol. Extract the ether in the separatory funnel with 25 mL of water followed by 25 mL of 10% sodium bicarbonate to remove unreacted benzoic acid. Again shake, with frequent release of pressure by inverting the separatory funnel and opening the stopcock, until no further reaction is apparent; then drain off the bicarbonate layer into a beaker. If this aqueous material is made strongly acidic with hydrochloric acid, unreacted benzoic acid may be observed. Wash the ether layer in the separatory funnel with saturated sodium chloride solution, and dry the solution over anhydrous calcium chloride in a 125-mL Erlenmeyer flask. Add sufficient anhydrous calcium chloride so that it no longer clumps together on the bottom of the flask. After 10 min, decant the dry ether solution into a dry 50-mL Erlenmeyer flask, wash the drying agent with an additional 5 mL of ether, and decant again. Remove the ether by evaporation in the hood. When evaporation is complete, add 2 to 3 spatula tips full of anhydrous calcium chloride to the residual oil and air dry for about 5 min longer.
14. SUPPLEMENTS (CONT.)

D. Chemiluminescence: The Synthesis of Luminol

Chemiluminescence is the process where a chemical reaction generates light. The reaction generates a product that is in an excited electronic state, which results in the emission of a photon, or light. Natural examples of chemiluminescence include the male firefly, but many other organisms can also emit light. When in search of a mate, the male firefly will emit flashes of light. This light is produced by the reaction of luciferin with molecular oxygen, which is catalyzed by the enzyme luciferase. A biochemical process that results in chemiluminescence, such as the example of the male firefly, is termed bioluminescence.
[pic]

Luminol is a compound that also undergoes chemiluminescence. One of its uses is by police, who use it to identify if blood is present at crime scenes. Luminol is to be synthesized from 3-nitrophthalic acid and hydrazine to produce 5-nitrophthalhydrazide, which is reduced by sodium dithionite to form luminol. When in an alkaline solution, luminol, or 5-aminophthalhydrazide, emits a blue-green light when mixed with hydrogen peroxide and potassium ferricyanide.

The mechanism of luminol’s light emitting reaction is not fully understood. It is thought to involve a peroxide, which then decays to form 3-diaminophthalate in a electronically excited triplet state (two unpaired electrons of the same spin). This then slowly undergoes an intersystem crossing to the singlet state (two unpaired electrons of different spin). The excited singlet state product then decays to the ground state, which results in the emission of light, a process which is called fluorescence.

[pic]

APPARATUS

A 5 ml conical vial, a hot plate, a heating block, a spin vane, Hirsch funnel, a 250 ml Erlenmeyer flask, and a thermometer.

PROCEDURE FOR THE SYNTHESIS OF LUMINOL

Heat a 5 mL vial containing 200 mg of 3-nitrophthalic acid and 0.4 ml of an aqueous 8% solution of hydrazine until the solid dissolves. Once dissolved, add 0.6 ml of triethylene glycol, and clamp the vial in a vertical position. Add a spin vane and insert a thermometer into the vile. Bring the solution to a vigorous boil to boil away the excess water. During this time, the temperature should be around 110