Hydrochloric Acid → 5-[3,6-Dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-N-(methylsulfonyl)-1,2-benzisothiazole-3-carboxamide

Beteiligte Stoffe

Reaktionsschritte

A solution of 5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-1,2-benzisothiazole-3-carboxylic acid (0.400 g, 1.08 mmol) in tetrahydrofuran is treated with 1,1'-carbonyldiimidazole (0.260 g, 1.58 mmol), stirred at room temperature for 30 minutes, refluxed for 2 hours, cooled to room temperature, treated dropwise with a solution of methanesulfonamide (0.130 g, 1.37 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.230 g, 1.50 mmol), stirred at room temperature for 3 hours, and poured into 0.5 N hydrochloric acid. The resultant aqueous mixture is extracted with methylene chloride. The organic extracts are combined, washed with brine, dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a residue. Column chromatography of the residue using silica gel and a methylene chloride/acetic acid solution (10:1) gives the title product as a white solid (0.350 g, 72%, mp 241-243° C.).

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