Acetic Anhydride → 3-Acetyl-7-chloro-2(3H)-benzothiazolone

Participants

Reaction Conditions

Reaction Steps

A mixture of 79.0 gm (0.32 mol) of [(2-chloro-6-nitro-phenyl)-thio]acetic acid, 150.0 gm (1.83 mol) of anhydrous sodium acetate and 600 ml of acetic acid anhydride was heated for 30 minutes at 100° C. The acetic acid anhydride was distilled off in an aspirator vacuum, the residue was stirred with 1 liter of water, and the precipitate was collected by suction filtration. After purification by chromatography on silica gel, using dichloromethane/ethyl acetate (volume ratio 1:1) for elution, the product was recrystallized from ethanol. 19.2 gm (26% of theory) of colorless crystals with a melting point of 74° C. were obtained.

Provenance & Evidence