Chlorosuccinimide → HCID 14330450, compound

Participants

Reaction Steps

To a solution of 10 g of 8-methoxy-3,4-dihydro-2H-[1]-benzothiopyran-3-carboxylic acid in 200 ml of methylene chloride is added 6.2 g of N-chlorosuccinimide in portions. After 10 minutes 60 g of silica gel is added. The reaction mixture is stirred for 15 minutes, filtered through 40 g of silica gel eluting with ether/methylene chloride (1:1). The solvent is concentrated to 100 ml, 5 ml of triethylamine and 5 g of ethyl chloroformate are added. After concentration 5 g of sodium azide in 60 ml of dimethylformamide are added and the reaction mixture is stirred for 1 hour. After dilution with water the products are extracted with ether, the ether extract is dried and evaporated to dryness; 150 ml of 10% aqueous sulfuric acid is added and the reaction mixture is heated under reflux for 2 hours. The reaction mixture is extracted with ether, the ether extract is washed with dilute sodium bicarbonate solution, dried and evaporated to dryness. Crystallization from methanol affords 8-methoxy-3,4-dihydro-2H-[1]-benzo-thiopyran-3-one, m.p. 60°.

Provenance & Evidence