Courtney Courter
Organic Chemistry (Night)
October 7, 2010
Lab Experiment #5 Bromination of Stilbene
Purpose of the Experiment: To make dihalides by brominating alkenes.
Material: 1 gram of stilbene, 30 mL diethyl ether, addition 15 dimethyl ether (5 ml and
than 10mL), 7 mL of 5% Bromine solution
Equipment: 100 mL round bottom flask, Claisen adapter, 125 mL seperatory funnel,
condenser, oven, stirring rod, Keck clip, buret, glass stopped, suction filtration
equipment, buchner funnel, melting point
Procedure: Dry the 100 mL round bottom flask, Claisen adapter, 125 mL seperatory
funnel, and condenser in the oven for a half hour. Place 1 gram of stilbene into the 100
mL round bottom flask. Add 30 mL of diethyl ether and stir under hood. Use the dried
claisen adapter and condensor (attached by the keck clip) to attach to the round bottom
flask. Obtain 7 mL of 5% Bromine solution and put it into the 125 mL separatory funnel.
Cover the funnel with a glass stopper. Connect the funnel to the claisen adapter. Transfer
the bromine into the round bottom flask over a period of ten minutes. (dropwise) After
completion stir for 15 more minutes until complete discoloration of bromine. Suction
Filtrate out your solid. You may use extra 5 mL of ether to transfer the solid. Wash the
solid on ur funnel with 10mL of ether to remove traces of bromine. Set the solid aside to
dry for a week. Than determine weight and melting point.
Table of Physical Constants:
The 4 Possible Compounds
Stilbene
Molecular
Weight
180.25 g/mol
Melting Point
122-125 °C (E Stilbene)
Bromine
136.2 g/mol
Diethyl Ether
-7.2 °C
-116.3 °C
74.12 g/mol
Meso stilbene dibromide
340 g/mol
236-240ºC
Observations: As we continued to ass drops of bromine and stir the color became a light
orange. The solid was a white-ish color.
Data Collected:
Weight of solid product
Melting Point of solid Product
Data
1.247
240 – 250 ºC
Evaluation: Based on the melting points and weights we can determine that the two
compounds of the mixture are most likely the E isomer of Meso stilbene dibromide
Courtney Courter
Organic Chemistry (Night)
Final Report:
a. Theoretical Yield:
b. Actual Yield and percent:
c. MP Range:
d. Newman Projection:
e.
October 7, 2010