Tetrahydrothiopyran-4-one → 10-amino-3,4-dihydro-7-methyl-1H-thiopyrano[4,3-b]quinoline

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-methylanthranilonitrile (4.46 g) and freshly fused zinc chloride (6.8 g) in 20 ml of nitrobenzene was heated at 50° C. for 1 hour. To this was added tetrahydrothiopyran-4-one (5.1 g) and the mixture was heated to 130° C. for 1.5 hours. After cooling, the zinc complex was filtered, rinsed with ethyl ether and partitioned between 2-butanone (MEK) and NH4OH. The aqueous phase was extracted with MEK and the organics were washed with water and dried (saturated NaCl, MgSO4). This was concentrated to give 4.76 g of an off-white powder, m.p. 239°-245° C. d., which was recrystallized from ethyl acetate to give 2.95 g of an off-white powder, m.p. 243°-246° C. d.

Provenance & Evidence