Hydrochloric Acid → Diethyl 2-(benzo-1,2,3-thiadiazol-7-yl)malonate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4.8 g of magnesium chloride in 50 ml of acetonitrile are treated with 7.6 ml of diethyl malonate and 14 ml of triethylamine, with ice-cooling and stirring. The mixture is stirred for 20 minutes and then treated at 0°-5° C. with portions of a suspension of 9.6 g of benzo-1,2,3-thiadiazole-7-carboxylic acid chloride in 50 ml of acetonitrile, the temperature being maintained at between 5° C. and 15° C. The resulting beige suspension is stirred for a further hour in an ice-bath at 0° C. and subsequently overnight at room temperature. On the next day, it is cooled again to 0° C., brought to pH 4.5 using 15% hydrochloric acid, and extracted with ethyl acetate. The extracts are dried over sodium sulfate, filtered over silica gel and evaporated. This results in the title compound in a yield of 83.2% of theory and with a melting point of 72°-74° C.

Herkunft & Nachweise