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, with vigorous stirring, to a solution of (S)-3-hydroxysulphonyloxymethyl-1,2,3,4-tetrahydroisoquinoline (100 g) in 0.25N sodium hydroxide solution (4000 cc). The reaction is exothermic. A solid precipitates. Stirring is continued for a further 3 hours and then the reaction mixture is neutralised by the addition of 4N hydrochloric acid. The resulting crystals are filtered off, washed copiously with water and then recrystallised from ethanol (3000 cc). (S)-1,5,10,10a-Tetrahydrothiazolo[3,4-b]isoquinoline-3-thione (77 g) is thus obtained in the form of fine white needles melting at 150° C.

Provenance & Evidence