methyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide → HCID 178481148, compound

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Reaction Steps

A mixture of methyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide (2.95 g) and 2-amino-7-hydroxy-2,4,6-cycloheptatrien-1-one (1.5 g) in xylene (103 ml) was refluxed for 52 hours. The reaction mixture was cooled to room temperature. The crystals were collected by filtration and washed successively with N,N-dimethylformamide and chloroform to give 4-hydroxy-N-(7-hydroxy-1-oxo-2,4,6-cycloheptatrien-2-yl)-2-methyl-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide (3.7 g).

Provenance & Evidence