2-Amino-6-methyl-2,4,6-cycloheptatrien-1-one → 4-hydroxy-2-methyl-N-(6-methyl-1-oxo-2,4,6-cycloheptatrien-2-yl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide

Participants

Reaction Steps

A solution of methyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide (1.2 g) and 2-amino-6-methyl-2,4,6-cycloheptatrien-1-one (0.7 g) in xylene (21 ml) is refluxed for 8 hours. The reaction mixture is then allowed to stand at room temperature for 2 days. The crystals that have separated out are collected by filtration, washed with toluene and recrystallized from dimethylformamide to give 4-hydroxy-2-methyl-N-(6-methyl-1-oxo-2,4,6-cycloheptatrien-2-yl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide (0.8 g), m.p. 276°-280° C.

Provenance & Evidence