Methyl 4-methylbenzoate → Methyl 4-(bromomethyl)benzoate

A methyl 4-methylbenzoate (MMB) solution (110 g, 0.73 mol) in CB (150 g) in a 250 mL round bottomed flask was heated by a heating mantle connected to a temperature controller to temperatures between 136 to 140° C. Liquid bromine (84.4 g, 0.53 mol or ~72 mol %), (Aldrich, 99.5+%, A.C.S. reagent) was fed via Viton tubings using Cole-Parmer computerized Drive with Easy-Load pump head. The bromine feed rate was adjusted to 0.50 mL/minute throughout the 52 minutes of addition time. Heating and stirring were continued for a few minutes after all bromine had been added, and then the reaction mixture was allowed to cool down. The "smoking" orange mixture was transferred to a separatory funnel and was washed with water (250 mL) to produce a colorless organic phase. The bottom layer (organic) was separated and concentrated under reduced pressure (rotary evaporator) to remove most of the chlorobenzene. The residual oily mixture was allowed to stand overnight. An impure crystalline solid was obtained. The crude solid was dissolved in 20% aqueous ethanol solution (450 mL) and allowed to cool in a refrigerator for 2 hours. The resulting white crystals were washed with 50% aqueous ethanol (200 mL) to produce 50.5 g (42% based on added bromine) of highly pure (~99%) material. No attempt was made to optimize the recovered yield.

1. customconnected to a temperature controller to temperatures between 136 to 140° C
2. temperatureHeating
3. waitwere continued for a few minutes
4. temperatureto cool down
5. customThe "smoking" orange mixture was transferred to a separatory funnel
6. washwas washed with water (250 mL)
7. customto produce a colorless organic phase
8. customThe bottom layer (organic) was separated
9. concentrationconcentrated under reduced pressure (rotary evaporator)
10. customto remove most of the chlorobenzene
11. customAn impure crystalline solid was obtained
12. temperatureto cool in a refrigerator for 2 hours
13. washThe resulting white crystals were washed with 50% aqueous ethanol (200 mL)
14. customto produce
15. customyield

ORD record

ord-86c1ebd5df2244349b844461e6ce195c

Source dataset

uspto-grants-2000_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06103926