4-[(4,5-dihydro-2-thiazolyl)amino]tetrahydro-3,5-bis(phenylmethylene)-2H-thiopyran-4-ol → 2,3,8,9-Tetrahydro-5-phenyl-9-(phenylmethylene)-5H,6H-thiazolo[3,2-a]thiopyrano[4,3-d]pyrimidine

Participants

Reaction Steps

A slurry of the 4-[(4,5-dihydro-2-thiazolyl)amino]tetrahydro-3,5-bis(phenylmethylene)-2H-thiopyran-4-ol (2.0 g, 5.1 mmole) from part A in 20 ml dry toluene under nitrogen at room temperature is treated with 12 ml of a solution of TiCl4 in toluene (1.29 g, TiCl4 in 25 ml). The resulting mixture is heated at reflux temperature for 2 hours. Upon cooling, the solid mass is pulverized and collected by filtration. The solids are partitioned between CHCl3 and aqueous NaHCO3. The aqueous layer is extracted with additional CHCl3. The extracts are washed (H2O), combined, dried (CaCl2) and concentrated on a steam bath; a volume of 75-100 ml is maintained by periodic addition of MeOH. When precipitation commences, the flask is cooled to room temperature. The product is collected, washed (MeOH) and dried in vacuo (80°) for several hours to give 1.5 g (79%) of product, m.p. 195°-196° d.

Provenance & Evidence