Water → 1-Methyl-3-[3-(4-methyl-1,3-dioxolan-2-yl)-1,2-benzisothiazol-5-yl]-6-(trifluoromethyl)uracil

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Reaction Steps

A mixture of 5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-1,2-benzisothiazole-3-carboxaldehyde (0.500 g, 1.41 mmol), 1,2-propanediol (0.130 ml, 1.83 mmol), p-toluenesulfonic acid (0.0100 g, 0.0100 g, 0.071 mmol) and toluene is stirred at reflux with azeotropic removal of water overnight, cooled to room temperature, diluted with diethyl ether, washed twice with water and once with brine and dried over anhydrous magnesium sulfate. Concentration in vacuo affords a yellow oil, which is chromatographed on silica gel to afford the title compound as a yellow solid (0.510 g, 87.6%, mp 81-83° C.) which is identified by NMR spectral analysis.

Provenance & Evidence