(S)-3-Methylthio-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinolinium iodide → (S)-3-[(3-Butylisoquinol-5-yl)imino]-1,5,10,10a-tetrahydrothiazolo[3,4-b]-isoquinoline

Participants

Reaction Steps

(S)-3-Methylthio-1,5,10,10a-tetrahydrothiazolo-[3,4-b]isoquinolinium iodide (5.25 g) is added to a solution of 5-amino-3-butylisoquinoline (3 g) in pyridine (100 cc). The suspension obtained dissolves gradually. After 4 days at a temperature of about 20° C., the mixture is concentrated to dryness under reduced pressure (25 mm Hg) at 50° C. The residue is dissolved in chloroform (200 cc). This solution is washed with N aqueous sodium hydroxide solution (3×100 cc) and then with water (2×50 cc), dried over sodium sulphate, filtered and the filtrate is then concentrated to dryness under reduced pressure (40 mm Hg) at 40° C. The residue obtained is recrystallised from diisopropyl ether (50 cc). (S)-3-[(3-Butylisoquinol-5-yl)imino]-1,5,10,10a-tetrahydrothiazolo[3,4-b]-isoquinoline (3.05 g), which melts at 82° C., is thus obtained.

Provenance & Evidence