反应详情

温度

100 °C

The process is performed as in Example 3, starting with 3.9 g of diastereoisomer A of the N-(tert-butyl)-N′-((1S)-1-benzyl-2-hydroxypropyl)thiourea in 46 cm3 of aqueous 6N hydrochloric acid. After heating for 5 hours at a temperature in the region of 100° C., the reaction mass is concentrated under reduced pressure (5 kPa) at a temperature in the region of 50° C. The oil obtained is dissolved in 50 cm3 of water; the solution is washed with twice 50 cm3 of dichloromethane. The aqueous phase is made alkaline by addition of 3 cm3 of 30% caustic soda and then extracted with 3 times 50 cm3 of dichloromethane. The organic extracts are combined and dried over sodium sulfate. After filtration and concentration under reduced pressure (5 kPa) at a temperature in the region of 40° C., 2.5 g of (−)-(4S,5S)-4-benzyl-5-methyl-4,5-dihydro-1,3-thiazol-2-ylamine are obtained in the form of a white solid melting at 89° C. (trans isomer). (αD20=−87.3±1.3 at a concentration of 0.5% in methanol).

1. concentrationthe reaction mass is concentrated under reduced pressure (5 kPa) at a temperature in the region of 50° C
2. customThe oil obtained
3. washthe solution is washed with twice 50 cm3 of dichloromethane
4. additionby addition of 3 cm3 of 30% caustic soda
5. extractionextracted with 3 times 50 cm3 of dichloromethane
6. dry with materialdried over sodium sulfate
7. filtrationAfter filtration and concentration under reduced pressure (5 kPa) at a temperature in the region of 40° C., 2.5 g of (−)-(4S,5S)-4-benzyl-5-methyl-4,5-dihydro-1,3-thiazol-2-ylamine