Chlorosulfonyl isocyanate → 5-Cyano-2-ethoxy-4-methoxy-benzoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of 2-ethoxy-4-methoxy-benzoic acid ethyl ester (1.5 g, 6.7 mmol) in 1,2-dichloroethane (2 mL) was added chlorosulfonyl isocyanate (0.923 mL, 10.6 mmol, in 1 mL of 1,2-dichloroethane) in several portions. The reaction was stirred at 50° C. overnight. Reaction was diluted with methylene chloride (2 mL) and water (1 mL), and extracted. The organic layer was washed with brine and concentrated in vacuo. Purification of the crude residue by flash column chromatography (silica gel, eluting with a gradient of ethyl acetate in hexanes) gave 900 mg (54% yield) of 5-cyano-2-ethoxy-4-methoxy-benzoic acid ethyl ester. LC-MS: 236.2 [(M+H—CH3)+].

Provenance & Evidence