Conditions of the Dieckmann condensation of alkyl 2-(N-methyl-N-(alkoxycarbonylmethyl) sulfamoyl) benzoates

M Pátek, F Hampl

Index: Patek, Marcel; Hampl, Frantisek Collection of Czechoslovak Chemical Communications, 1989 , vol. 54, # 12 p. 3267 - 3277

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Citation Number: 6

Abstract

Abstract The Dieckmann condensation of alkyl 2-(N-methyl-N-(alkoxycarbonylmethyl) sulfamoyl) benzoates IIIa-IIIe with various bases affords alkyl 4-hydroxy-2-methyl-2H-1, 2- benzothiazine-3-carboxylate 1, 1-dioxides IVa-IVe which are intermediates in the synthesis of antiinflammatory drug piroxicam. The yields of benzothiazines IVa-IVe depend mostly on the nature of a base, reaction temperature and solvent used for these condensations. ...