反应详情

39 Parts of thionyl chloride are added dropwise, in a manner ensuring that the internal temperature does not exceed 50° C., to a solution of 45 parts of 3-hydroxymethyl-6-chloro-oxazolo[4,5-b]pyridin-2-(3H)-one in 200 parts of toluene; and the whole is stirred for a further 4 hours at 40°-50° C. The resulting solution is subsequently freed from gases in a water-jet vacuum, and sufficient toluene is evaporated off to leave a crystal sludge that can still just be stirred. After the addition of 100 parts of hexane, filtration is carried out and the filter cake is washed twice with cold hexane. There are obtained 40 parts of 3-chloromethyl-6-chloro-oxazolo[4,5-b]pyridin-2-(3H)-one (83% of theory), m.p. 105°-107° C.

1. customis evaporated off
2. customto leave a crystal sludge that
3. stirringcan still just be stirred
4. washthe filter cake is washed twice with cold hexane