1,4-Dibromobenzene → Benzene, 1-bromo-4-(2-propenyl)-

At 5° C., a solution of allylbromide (5.64 g, 46.6 mmol) in THF (40 mL) is slowly added to the Grignard reagent freshly prepared from 1,4-dibromobenzene (10.0 g, 42.4 mmol) and Mg-turnings (1.13 g, 46.6 mmol) in THF. The reaction mixture becomes slightly warm and a fine precipitate forms. Upon completion of the addition, the suspension is stirred at rt for 1 h before it is diluted with diethyl ether and washed with two portions of 1 N aq. HCl and one portion of water. The wash solutions are extracted twice with diethyl ether. The organic extracts are combined, dried over MgSO4 and evaporated. The crude product is purified by CC on silica gel eluting with heptane:EA 9:1 to give 1-allyl-4-bromo-benzene (5.50 g) as a colourless oil.

1. temperatureThe reaction mixture becomes slightly warm
2. additionUpon completion of the addition
3. washwashed with two portions of 1 N aq. HCl and one portion of water
4. extractionThe wash solutions are extracted twice with diethyl ether
5. dry with materialdried over MgSO4
6. customevaporated
7. customThe crude product is purified by CC on silica gel eluting with heptane:EA 9:1

ORD record

ord-cab4f33b0f2a4f49a42d346178397aea

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07846964B2