反应详情

A suspension of (RS)-5-hydroxymethyl-6-[(pyrid-3-yl)thiocarbamoyl]-4,5,6,7-tetrahydrothieno[2,3-c]pyridine (2.3 g) in 6 N hydrochloric acid (34 cc) is heated under reflux for 2 hours. The resulting brown solution is decolorised with animal charcoal and filtered. The filtrate is rendered alkaline to pH 11 with a 15% aqueous solution of potassium carbonate and extracted with methylene chloride (150 cc and then 3×100 cc). The organic extracts are combined and dried over sodium sulphate. After filtering and concentrating the filtrate to dryness under reduced pressure (25 mm Hg; 3.3 kPa) at 40° C., an oil is obtained which crystallises slowly. This oil is dissolved in a mixture, heated under reflux, of isopropanol and diisopropyl ether (4:1 by volume; 100 cc). The solution is cooled at +5° C. for 20 hours. The solid is filtered off, washed with diisopropyl ether (50 cc) and dried at 60° C. under reduced pressure (0.1 mm Hg; 0.013 kPa). (RS)-7-[(Pyrid-3-yl)imino]-4,4a,5,9-tetrahydrothiazolo[ 3,4-a]thieno[3,2-d]pyridine (1.2 g) is obtained in the form of white crystals melting at 136° C.

1. temperatureis heated
2. temperatureunder reflux for 2 hours
3. filtrationfiltered
4. extractionextracted with methylene chloride (150 cc
5. dry with materialdried over sodium sulphate
6. filtrationAfter filtering
7. concentrationconcentrating the filtrate to dryness under reduced pressure (25 mm Hg; 3.3 kPa) at 40° C.
8. customan oil is obtained which
9. customcrystallises slowly
10. dissolutionThis oil is dissolved in a mixture
11. temperatureheated
12. temperatureunder reflux, of isopropanol and diisopropyl ether (4:1 by volume; 100 cc)
13. temperatureThe solution is cooled at +5° C. for 20 hours
14. filtrationThe solid is filtered off
15. washwashed with diisopropyl ether (50 cc)
16. customdried at 60° C. under reduced pressure (0.1 mm Hg; 0.013 kPa)