Hydrochloric Acid → m-Phenoxybenzyl 2-bromo-3-methyl-3-butenoate

참여 물질

반응 단계

A 100 ml flask is flushed with nitrogen and to it is added 25 ml of a 1 M THF solution of lithium N-isopropylcyclohexylamide (0.025 mole) followed by HMPT (5 ml). The flask is cooled to -78° and 7.1 g (0.025 mole) of m-phenoxybenzyl 3-methyl-2-butenoate in THF (25 ml) is added dropwise over 5 minutes. After the addition the mixture is stirred at -20° for 1 hour. This cold solution is then added dropwise to 1.1 equivalent of bromine in THF at -78°. After a further 1 hour at -78°, 5 ml of concentrated hydrochloric acid is added and the mixture allowed to come to RT and poured into ether plus cold aqueous hydrochloric acid. The ether layer is washed with water and brine and dried over calcium sulfate. Removal of the solvent gives m-phenoxybenzyl 2-bromo-3-methyl-3-butenoate, which is reacted with p-methylaniline by the process of Example 5 to give m-phenoxybenzyl ester of 2-(p-methylphenylamino)-3-methyl-3-butenoate.

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