Reaktion #6458

Reaktionsgleichung

hydrochloric acid

benzo-1,2,3-thiadiazole-7-carboxylic acid chloride

magnesium chloride

diethyl malonate

→

title compound

Ausbeute 83.2%

diethyl 2-(benzo-1,2,3-thiadiazol-7-yl)malonate

Ausbeute 83.2%

Lösungsmittel

acetonitrile

acetonitrile

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling
2. 2
   workup.STIRRINGThe mixture is stirred for 20 minutes
3. 3
   Temperaturthe temperature being maintained at between 5° C. and 15° C
4. 4
   workup.STIRRINGThe resulting beige suspension is stirred for a further hour in an ice-bath at 0° C. and subsequently overnight at room temperature
5. 5
   Extraktionextracted with ethyl acetate
6. 6
   TrocknenThe extracts are dried over sodium sulfate
7. 7
   Filtrationfiltered over silica gel
8. 8
   Sonstigeevaporated

Vorschrift

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.

Quelle