AZARDS ABLE OF REAGENTS - Amazon...

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The Grignard Reaction May 30 2012 Cheryl Lee 100191898 HAZARDS / TABLE OF REAGENTS Chemical Name / Molecular / Structural Formula Grignard reagent | Phenylmagnesium bromide solution, C6H5BrMg Extremely flammable; Corrosive 1,1-diphenylethanol, C14H14O Eye, skin, GI tract, respiratory tract irritant Acetophenone, C6H5COCH4 Combustible; Eye, skin, GI tract, respiratory Biphenyl (C12H10) Harmful if inhaled or absorbed through skin

Transcript of AZARDS ABLE OF REAGENTS - Amazon...

Page 1: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

HAZARDS / TABLE OF REAGENTS

Chemical Name / Molecular / Structural Formula

Physical Appearance | bp | mp

Molecular Weight | Density | Solubility

Hazards

Grignard reagent | Phenylmagnesium bromide solution, C6H5BrMg

Clear, colorless solution

F.W.181.31 g/mol Conc: 3.0 M in diethyl ether Density: 1.134 g/mL at 25 °C Solubility: Reacts explosively w/ H2O

Extremely flammable; Corrosive

1,1-diphenylethanol, C14H14O

white to pale yellow crystals bp: 162 °C mp: 77-81 °C

MW: 198.26 Vapor Density: 6.84 Solubility: H2O soluble

Eye, skin, GI tract, respiratory tract irritant

Acetophenone, C6H5COCH4

Colorless to light yellow liquid Boiling Point: 201.7°C (395.1°F) Melting Point: 19.7°C (67.5°F)

MW: 120.16 g/mole

Vapor Density: 4.1 (Air = 1)

Solubility: Soluble in methanol, diethyl ether. Partially soluble in cold water, hot water.

Combustible; Eye, skin, GI tract, respiratory tract irritant

Biphenyl (C12H10)

Colorless leaflets; pleasant peculiar odor mp/bp: 68.93 / 256.1 °C

MW: 154.207 g/mol Solubility: I H2O; s EtOH, eth; vs bz, ctc. MeOH

Harmful if inhaled or absorbed through skin

Page 2: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Chemical Name / Molecular / Structural Formula

Physical Appearance | bp | mp

Molecular Weight | Density | Solubility

Hazards

Bromobenzene, C6H5Br

Clear, colorless liquid Boiling Point: 156.2°C (313.2°F) Melting Point: -30.6°C (-23.1°F)

MW: 157.02 g/mole Vapor Density: 5.41 (Air = 1) Solubility: Soluble in methanol, diethyl ether. Very slightly soluble in cold water.

Very hazardous in case of skin contact (irritant, permeator), of eye contact (irritant), of inhalation.

Dichloromethane9 CH2CL2

Colorless liquid Very soluble in benzoic acid Eye and skin irritant; respiratory tract irritation

Sulfuric acid, H2SO4

Clear colorless to yellow liquid bp: 290-338 °C mp: 10 °C

MW: 98.07 Vapor Density: 3.38 (air=1) Solubility: Soluble w/ much heat

Causes eye and skin, digestive and respiratory tract burns;

Iodine, I2

Purple solid with metalic luster. (Dark.) Boiling Point: 184.4°C (363.9°F) Melting Point: 113.7°C (236.7°F)

MW: 253.81 g/mole Dispersion Properties: See solubility in water, methanol, diethyl ether. Solubility: Easily soluble in diethyl ether. Soluble in methanol. Very slightly soluble in cold water, hot water.

Eye and skin irritant; respiratory tract irritation; non-flammable

Magnesium sulfate anhydrous MgSO4 anhydrous10

Solid; non-flammable Easily soluble in cold water Slightly hazardous in case of skin contact (irritant), of eye contact (irritant), of inhalation.

Page 3: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Chemical Name / Molecular / Structural Formula

Physical Appearance | bp | mp

Molecular Weight | Density | Solubility

Hazards

Methyl benzoate, C8H8O2

colourless to light yellow fragrant liquid bp: 199°C mp: -12°C

MW: 136.15 g/mol Density: 1.088 g/mL at 20 °C (lit.) Solubility: Slightly soluble in water. Hydrolyzes slowly in contact with water

Combustible. Incompatible with strong oxidizing agents, strong acids, strong bases.

Eye and skin irritant; respiratory tract irritation;

Sodium sulfate anhydrous, Na2SO4

White crystalline powder Boiling Point: 1100°C (2012°F)Melting Point: 888°C (1630.4°F)

MW: 142.06 g/mole Solubility: Soluble in cold water, hydrogen iodide, and glycerol.. Insoluble in alcohol.

Non-flammable; Eye and skin irritant; respiratory tract irritation;

Petroleum Ether

Clear, colorless liquid Flammable bp: 60°C mp: -73°C

Negligible solubility in H2O Skin and eye irritant ; Skin permeator

Triphenylmethanol, C19H6O

White powder bp: 360 °C mp: 160-163 °C

MW: 260.33 g/mol Solubility: Insoluble in H2O; Combustible. Incompatible with oxidizing agents, acids, acid chlorides, acid anhydrides.

Page 4: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Flow Chart

Set up Apparatus /

Starting Materials

o Obtain clean dry glass-ware from oven: boiling tube (25 mm x 200 mm), two

Pasteur pipettetes, one test tube (10 mL)

o Handle hot glass-ware w/ oven gloves

o Ensure all glass-ware are DRY

o Prep in FUME HOOD 1 mL bromobenzene in 5 mL anhydrous diethyl ether in

10 mL test tube

o Use Pasteur pipettetes to measure out the amounts

Prep Grignard

Reagent | Initiate

reaction

o Place ~ 0.30 g Magnesium turnings into dry boiling tube

o Add ~ 2 mL of prepared bromobenzene solution in dry ether

o Mount/clamp test tube on ring stand in FUME HOOD

o Wait till the mixture boil/bubble and become grey/turbit

o If no bubbling, initiate reaction by crushing small magnesium w/ clean dry

stirring rod against test tube bottom

o Alt: add small crystal of iodine to test tube

o Place test tube in warm water bath as needed

o Ensure diethyl ether not boil off to MAINTAIN Vol

o Cool test tube in a beaker of H2O if reaction becomes too vigorous

o After several minutes, add remaining 4 mL ethereal bromobenzene solution

in small portions to maintain reaction rate

o Upon stopping of spontaneous boiling, place test tube in a beaker of warm

water (40-50 °C) for 5 Min

Page 5: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Prep

Triphenylmethanol

o Dissolve 0.6 mL methyl benzoate in 5 mL of anhydrous

ether

o Add solution of methyl benzoate DROPWISE to Grignard

reagent solution (NOTE COLOR CHANGES)

o Avoid evaporation by adding more dry ether to maintain

initial solvent volume

o Reaction complete when bubbling stops

o Add ice and 6 M H2SO4 to destroy excess magnesium a

DROPPER full at a time until frothering stops

o Place reaction tube in warm water bath (~ 50 C) until

boiling stops to Drive off remaining solvent

Prep 1,1-Diphenylethanol

o Dissolve 1.0 mL of

acetophenone in 5 mL

anhydrous ether

o Add acetophenone solution

dropwise to Grignard reagent

solution (note any COLOR

CHANGES)

o Maintain initial solvent

volume!! Prevent excess

solvent evaporation by adding

more dry ether

o Reaction would be complete

when bubbling stops

Page 6: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Isolation of alcohol

product o Add 10 mL DCM and 15 mL H2O

to reaction mixture

o Transfer contents to sep funnel

o Rinse boiling tube w/ H2O and

DCM (small portions)

o Combine washings in sep funnel

o Mix layers

o Drain bottom organic layer via

stopcock

o Pour top aqueous layer into beaker

via funnel top (discarded later)

o Wash organic layer w/ 5 mL of 10

% NaHCO3 and mix

o Remove organic layer (bottom layer)

and throw out aqueous layer

o Wash organic layer again w/

another 5 mL of H2O

o Dry w/ MgSO4 or Na2SO4 to get

rid of DCM

o Filter dried organic layer by gravity

Page 7: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

o Further evaporation by adding 5 mL

petroleum ether and warming on

hot water bath

o Place Erlenmeyer flask in ice bath to

allow crystal precipitation

o If not, then transfer solvent/crystals

mixture to 5 mL round bottom flask

o Attach Claisen head

o Concentrate mixture under reduced

pressure

o Warm flask slightly to facilitate

evaporation

o Wash recovered crystals 2X w/

small amounts of petroleum ether

o Save filrate for TLC and GC

analysis

o Determine mass of crude product

o Save some for mp analysis

o Dissolve remaining white crystalline

product in minimal amount of

DCM in 10 mL Erlenmeyer flask

Add ~ 5 mL petroleum ether

Page 8: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

o Recrystallize at rm temp

o Recrystallize in ice water bath to obtain alcohol product

o Collect crystals by vacuum filtration

o Obtain second crop of crystals Transfer mother liquor to separate 10 mL Erlenmeyer flask

o Evaporate on hot water bath for a few seconds or until crystals precipitate

o Place in ice water bath

o Use remaining mother liquor to collected crystals by vacuum filtration

o Wash combined crystals in petroleum ether (2x2 mL)

o Allow to dry

Analysis of alcohol products

o Obtain mass

o Obtain mp of dried product

o Collect IR spectrum of starting material used

o Collect IR spectrum for alcohol product

o Submit product in sample bag

o Run TLC analysis (5:1 petroleum ether/ethyl acetate as eluting solvent)

o On alcohol product

o On filtrate from initial crystallization (may be diluted by a factor of 100)

o Authentic biphenyl

o GC analysis of filtrate from initial crystallization from each Grignard process

Page 9: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Balanced Equation:

Reaction Mechanism:

CHEM 322L Experiment 1: Grignard Reaction 2

and adds to the carbonyl carbon forming an alkoxide. In the workup of the

reaction, an acid is added so that the alkoxide is protonated to form the alcohol

product. See Figure 2 for the general reaction.

RC

R

O

R R

OHR1) RMgX

2) H2O

1) addition

2) protonation

yields a 3o

alcohol

RC

H

O

R R

OHH1) RMgX

2) H2O

1) addition

2) protonation

yields a 2o

alcohol

R Xether

R MgX

Mg

R MgX

Figure 1. General reaction for the Grignard reaction.

In this experiment, you will be performing a Grignard reaction (see Figure 3).

You will first synthesize the Grignard reagent starting from bromobenzene and

magnesium using ether as the solvent. The reaction and thus the reagent are

moisture sensitive so you will be using anhydrous ether. In the second step, you

will be adding your Grignard reagent to benzophenone to form triphenylmethanol.

Figure 3. The overall reaction of this experiment.

Br

Bromobenzene

bp 156 oC

M.W. 157.02

density 1.491 g/mL

M agnes iu m A t. W. 2 4 . 31

Phenylm agne s iu m br omidean inter m ediat e b u t n ot isolated

+

1) ether+

T r iphe ny lm e thanol

mp 1 60 - 16 3

oC

M . W . 26 0. 34

2) dilute HCl

M gB r

M g B r

Pheny lm a gn es ium br o m ide

anhydrous

diethyl ether(ether)

O

Benzophenone

mp

48-49

oC

M.W. 182.22 .

O H

M g

Page 10: AZARDS ABLE OF REAGENTS - Amazon S3s3.amazonaws.com/prealliance_oneclass_sample/O40DWw5O4Y.pdfKwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011) 2. thZubrick, J. The

The Grignard Reaction May 30 2012

Cheryl Lee 100191898

Reference:

1. Kwantlen Polytechnic University CHEM 2320/2420 Lab Manual (2011)

2. Zubrick, J. The Organic Chem Survival Manual: A Student’s Guide to Techniques, 7th ed.; Wiley: New Jersey, 2008.

3. MSDS for Phenylmagnsium bromide. http://www.sigmaaldrich.com/catalog/product/ALDRICH/257117?lang=en&region=CA

(accessed May 29 2012)

4. MSDS for 1,1-diphenylethanol. https://fscimage.fishersci.com/msds/79640.htm (accessed May 29 2012)

5. ScienceLab.com, Inc. MSDS for Acetophenone. http://www.sciencelab.com/msds.php?msdsId=9922778 (accessed May 29 2012)

6. MSDS for Bromobenzene. http://www.sciencelab.com/msds.php?msdsId=9927463 (accessed May 29 2012)

7. MSDS for Sulfuric acid. http://www.sciencelab.com/msds.php?msdsId=9927547 (accessed May 29 2012)

8. ScienceLab.com, Inc. MSDS for Sodium Bicarbonate. http://www.sciencelab.com/msds.php?msdsId=9927258 (accessed May 22

2012)

9. MSDS for Sodium sulphate anhydrous. http://www.sciencelab.com/msds.php?msdsId=9927278 (accessed May 29 2012)

10. MSDS for Triphenylmethanol. http://www.chemicalbook.com/ChemicalProductProperty_EN_CB3335936.htm (accessed May 29

2012)

11. MSDS for Petroleum Ether. http://www.sciencelab.com/msds.php?msdsId=9927688 (accessed May 22 2012) 12. Chem Department. The University of Missouri – Kansas City. The Grignard Reaction.

http://d.web.umkc.edu/drewa/Chem322L/Handouts/EXP%201%20grignard_reaction%20SP2008.pdf (accessed May 22 2012)