Toluene → (S)-3-chloro-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinolinium chloride

Participants

Reaction Conditions

Reaction Steps

A solution (20 cc) of phosgene in toluene (containing 2 mols of phosgene per liter) is added dropwise in the absence of moisture whilst stirring and at a temperature of about 20° C to a solution of (S)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinoline-3-thione (2.2 g) in tetrahydrofuran (25 cc). The mixture becomes cloudy after 15 minutes; it is stirred for 5 hours and heated at 50° C for 1 hour. The solvents are evaporated under reduced pressure (25 mm Hg) to give (S)-3-chloro-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinolinium chloride (2.6 g) in the form of a very hygroscopic white crystalline powder.

Provenance & Evidence