Sulfuric Acid → HCID 13338576, compound

Participants

Reaction Steps

To 92 parts of concentrated sulfuric acid are added portionwise 18.5 parts of 3,4-dihydro-2H-pyrimido[2,1-b]benzothiazole nitrate at 0° C. Upon completion, stirring is continued for 1 hour without cooling. The reaction mixture is poured onto 200 parts of ice-water and stirred for a while. The whole is alkalized with ammonium hydroxide and the product is extracted with trichloromethane. The extract is dried, filtered and evaporated. The residue is stirred in 2,2'-oxybispropane. The product is filtered off and dried, yielding 16.3 parts of 3,4-dihydro-8-nitro-2H-pyrimido[2,1-b]benzothiazole; mp. 247.6° C.

Provenance & Evidence