Preparation of ethyl 4-bromocrotonate
22.8 g of ethyl crotonate are dissolved in 40 ml of dry carbon tetrachloride and 35.6 g of N-bromosuccinimide are added to the obtained solution. In order to accelerate bromination reaction 0.2 g of benzoyl peroxide could be used. The mixture is heated under reflux for three hours, then cooled to o° C and filtered in order to separate insoluble succinimide. The filtrate is washed with water and organic (lower) layer is isolated with a separatory funnel, dried with sodium sulfate, filtered and distilled at atmospheric pressure in order to remove carbon tetrachloride (boiling point 77° C). Finally the crude ethyl 4-bromocrotonate is purified by distillation in vacuo. The fraction boiling below about 58° C/14 mm Hg is unchanged ethyl crotonate, meanwhile fraction boiling at 98-99° C/14 mm is pure ethyl 4-bromocrotonate. Ethyl 4-bromocrotonate is a colorless, mobile liquid having a strong pleasant odor. Yield of final product is 25 g.
Practical organic chemistry, by F. G. Mann, 177-178, 1960
Ethyl 4-bromocrotonate, 37746-78-4, (E)-Ethyl 4-bromobut-2-enoate, 4-bromocrotonic acid ethyl ester, ethyl (2E)-4-bromobut-2-enoate, 6065-32-3, Ethyl (E)-4-bromo-2-butenoate, Ethyl trans-4-bromo-2-butenoate, FHGRPBSDPBRTLS-ONEGZZNKSA-N, 2-Butenoic acid, 4-bromo-, ethyl ester, (E)-, 2-Butenoic acid, 4-bromo-, ethyl ester, ethyl (E)-4-bromanylbut-2-enoate, (E)-4-bromo-2-butenoic acid ethyl ester, ethyl (E)-4-bromobut-2-enoate, Ethyl4-bromocrotonate, ethyl-4-bromocrotonate, AC1NT13E, AC1Q31QJ, Ethyl .gamma.-bromocrotonate, E13830_ALDRICH, SCHEMBL199005, SCHEMBL199006, Jsp006654, CHEMBL3273390, MolPort-001-791-959, MolPort-023-197-992, BB_SC-5542, Ethyl (2E)-4-bromo-2-butenoate, EINECS 227-996-1, BBL011101, SBB070755, STK802345, ZINC01708358, Ethyl (2E)-4-bromo-2-butenoate #, AKOS005622630, RTR-015316, 4-bromo-trans-crotonic acid ethyl ester, AJ-30720, AK-68857, AK-68858, BC203933, CJ-06773, CJ-28963, KB-51225, SC-17679, SC-71037, AB0010378, AI3-52372, DB-049186, KB-190105, TL8003844, TR-015316, FT-0617887, FT-0626275, ST24020695, Z-4077, A823852, A832828, I14-7867, 3B3-005334
ethyl 4-bromobut-2-enoate, CID5373944