反应详情

4,4'-Dichlorodeoxybenzoin can be prepared by heating 4-chlorophenylacetic acid (85g) in thionyl chloride (59.5g) under reflux for 2.5 hours to yield 4-chlorophenylacetyl chloride (45.5g) which is subsequently dissolved in chlorobenzene (30g) and added dropwise with cooling to a stirred aluminium chloride (73g). The resultant mixture is cooled and stirred for a further 0.5 hours and then heated at 100° for one hour. The mixture was again cooled and poured into a mixture of conc. hyrochloric acid (200ml) and ice (1 liter) precipitate on standing crude 4,4'-dichlorodeoxybenzoin which on recrystallisation from methanol has a melting point of 115°-116°.

1. temperatureunder reflux for 2.5 hours