Hydrochloric Acid → HCID 20262420, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 75 parts of 2-benzothiazolamine, 76 parts of 3-acetyl-4,5-dihydro-2(3H)-furanone, 2,4 parts of a hydrochloric acid solution 12 N and 270 parts of methylbenzene was stirred and refluxed for 2 hours using a water-separator. The reaction mixture was cooled and 323 parts of phosphoryl chloride were added at a temperature between 20° and 25° C. The whole was slowly heated to 110° C. and stirring was continued for 2 hours at this temperature. The solvent was evaporated and the residue was poured onto a mixture of crushed ice and ammonium hydroxide. The product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (92:8 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2-propanol and 2,2'-oxybispropane, yielding 39 parts of 3-(2-chloroethyl)-2-methyl-4H-pyrido[2,1-b]benzothiazol-4-one; mp. 144° C. (intermediate 4).

Provenance & Evidence