Carbon Disulfide → (10aS)-1,5,10,10a-Tetrahydro-3H-[1,3]thiazolo[3,4-b]isoquinoline-3-thione

Participants

Reaction Steps

Carbon disulphide (40 g.) is added dropwise at 20° C., with vigorous stirring, to a solution of (S)-3-hydroxysulphonyloxymethyl-1,2,3,4-tetrahydroisoquinoline (100 g) in 0.25N sodium hydroxide solution (4,000 cc.). The reaction is exothermic. A solid precipitates and the reaction mixture then sets solid. Stirring is continued for 3 hours. The reaction mixture is neutralised by adding 4N hydrochloride acid. The crystals formed are filtered off, washed copiously with water and then recrystallised from ethanol (3,000 cc.) to give (S)-1,5,10,10a-tetrahydrothiazolo[3,4-b]-isoquinoline-3-thione (77 g. ) in the form of fine white needles melting at 150° C.

Provenance & Evidence