Réaction #65191

Équation de réaction

6-chloro-α-hydroxy-N,N-dimethyl-2-(2,5-dimethylthien-3-yl)imidazo[2,1-b]benzothiazole-3-acetamide

thionyl chloride

N,N-dimethyl formamide

→

α,6-dichloro-N,N-dimethyl-2-(2,5-dimethylthien-3-yl)imidazo[2,1-b]benzothiazole-3-acetamide hydrochloride

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   AutreThe solvent and the excess thionyl chloride are removed under reduced pressure
2. 2
   Lavagethe solid is washed with diethyl ether and it
3. 3
   Autreis dried

Mode opératoire

18 g (0.0431 mole) of 6-chloro-α-hydroxy-N,N-dimethyl-2-(2,5-dimethylthien-3-yl)imidazo[2,1-b]benzothiazole-3-acetamide are treated with 31 ml (0.43 mole) of thionyl chloride, 2 ml of N,N-dimethyl formamide and 100 ml of dichloromethane at the reflux temperature for 6 h. The solvent and the excess thionyl chloride are removed under reduced pressure, the residue is taken up in diethyl ether, the solid is washed with diethyl ether and it is dried. 21 g of α,6-dichloro-N,N-dimethyl-2-(2,5-dimethylthien-3-yl)imidazo[2,1-b]benzothiazole-3-acetamide hydrochloride are obtained which are reduced with 21 g (0.136 mole) of Rongalite® in 300 ml of dichloromethane at room temperature for 24 h. The solution is separated after settling has taken place, the solid is washed with dichloromethane, the organic phase is washed with a saturated sodium hydrogen carbonate solution and then with water, it is dried over sodium sulphate and the solvent is evaporated under reduced pressure. An oil is obtained which crystallizes and which is recrystallized from acetonitrile. 14.4 g of yellow needles are finally isolated. Melting point: 202°-203° C.

Source