Preparation of Methyl 2-Arylpropanoates by the Reaction of 2-Hydroxypropiophenone Dimethyl Acetals with Sulfuryl Chloride in the Presence of an Amide or a Weak Base

Treatment of 2-hydroxypropiophenone dimethyl acetals [p-RC6H4C(OMe)2CH(OH)Me] (1; R=H, i-Bu, OMe, Ph, Br) with sulfuryl chloride in the presence of an amide or a weak base affords methyl 2-arylpropanoates (2) in good to excellent yields via 1,2-aryl migration of 1. The hydrolysis of 2 leads to the corresponding acids, some of which are pharmaceutically important compounds having nonsteroidal anti-inflammatory and analgesic activities. The aryl migration proceeds stereospecifically with complete inversion of configuration at the β-carbon atom.

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