Water → 2-benzyl-4-hydroxy-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methylester-1,1-dioxide

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Reaction Steps

10.7 gm (0.035 mol of 4-hydroxy-2H-naphtho[2,1-e]1,2-thiazine-3-carboxylic acid methyl ester-1,1-dioxide and 15.0 gm (0.0875 mol) of freshly distilled benzyl bromide were added to a mixture of 33 ml of water and 120ml of ethanol, and then 38.5 ml of 1 N sodium hydroxide were added dropwise. After stirring for 24 hours at room temperature, the crystals which had formed were suction-filtered off, washed with water and dried. Recrystallization from ethylene chloride/petroleum ether yielded 11.9 gm (86% of theory) of 2-benzyl-4-hydroxy-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methylester-1,1-dioxide, m.p. 254°-156° C.

Provenance & Evidence