Hydrochloric Acid → 1,3-Dibenzyltetrahydro-1H-thieno[3,4-d]imidazole-2,4-dione

Participants

Reaction Conditions

Reaction Steps

After heating to 90° C. a mixture of 38.68 g of (+)-cis-1,3-dibenzylhexahydrofuro[3,4-d]imidazole-2,4-dione, 6.04 g of sodium acetate, 2.49 g of sulfur and 47.56 g of polyethylene glycol (the average molecular weight: 600), it was stirred for 4.5 hours at the temperature while blowing 4.50 g of hydrogen sulfide at a rate of 10 ml/minute. Then blowing of hydrogen sulfide was stopped and the resultant mixture was stirred for 5 hours at the temperature. After cooling the reaction mixture to room temperature, 173.61 g of toluene and 99.70 g of water were added to the mixture, and 8.25 g of zinc powder was further added to the mixture while stirring at room temperature. After dropping 54.90 g of 35% hydrochloric acid at the same temperature, the resultant mixture was stirred at 45° C. for 8 hours. The mixture was separated by removing water layer to give an oil layer, which was concentrated to give a product. Recrystallization from 2-propanol and water gave a crystal of (+)-cis-1,3-dibenzylhexahydrothieno[3,4-d]imidazole-2,4-dione. The yield was 36.96 g (yield percentage: 91%). Melting point was 126° C. [α]D20 was 90° C.=1.0; chloroform).

Provenance & Evidence