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, whilst stirring vigorously, to a solution of (S)-3-hydroxysulphonyloxymethyl-1,2,3,4-tetrahydroisoquinoline (100 g) in 0.25 N aqueous sodium hydroxide solution (4000 cc). The reaction is exothermic. A solid precipitates; the stirring is continued for 3 hours. The reaction mixture is then neutralised by the addition of 4 N hydrochloric acid. The resulting crystals are filtered off, washed copiously with water and then recrystallized 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 which melt at 150° C.

Provenance & Evidence