Methyl chloroacetate → 2-Benzo[1,3]dioxol-5-ylmethyl-4-hydroxy-1,1-dioxo-1,2-dihydro-1lambda6-benzo[e][1,2]thiazine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To 2-Benzo[1,3]dioxol-5-ylmethyl-1,1-dioxo-1,2-dihydro-1λ6 -benzo[d]isothiazol-3-one (1.115 g, 3.517 mmol) in DMSO(6 mL) was added methyl 2-chloroacetate (0.61 mL, 6.96 mmol). The mixture was heated to 40° C. and sodium hydride (0.562 g, 60% in oil, 14 mmol) was added slowly over 1 hour. The mixture was maintained at 40° C. for 3 h and then cooled to room temperature and diluted with 1N HCl (100 mL). The mixture was extracted with ethylacetate (2×100 mL) and the organic phase washed with brine and dried over MgSO4. Chromatography, silica gel, eluant CHCl3, and crystallization from methylene chloride/hexane afforded the required product (0.596 g, 44%);

Provenance & Evidence