反应详情

A mixture containing 3-methylamino-4-(2-mercaptoethylamino)-1,2,5-thiadiazole 1,1-dioxide (1.0 g; 4.5 mmoles) [prepared in Step A] and 5-dimethylaminomethyl-2-furanmethanol (0.82 g; 4.5 mmoles) [prepared according to the procedure in J. Chem. Soc., 4728 (1958)] in 20 ml of concentrated hydrochloric acid was stirred in an ice-water bath for 2 hours and then allowed to stand at 0° for 64 hours. The reaction mixture was stirred at ambient temperature for 23 hours, evaporated without heating under reduced pressure and the residue partitioned between water and methylene chloride. The aqueous phase was made basic with sodium bicarbonate and extracted with methylene chloride. The combined organic phase was washed with saturated brine solution, dried and evaporated under reduced pressure. The residue was placed on 25 g of silica gel and chromatographed using a gradient elution of methylene chloride-methanol. The appropriate fraction was evaporated and the product crystallized from methanol. Recrystallization from methanol yielded the title compound, mp 92°-96°.

1. customprepared
2. customevaporated
3. temperaturewithout heating under reduced pressure
4. customthe residue partitioned between water and methylene chloride
5. extractionextracted with methylene chloride
6. washThe combined organic phase was washed with saturated brine solution
7. customdried
8. customevaporated under reduced pressure
9. customchromatographed
10. washa gradient elution of methylene chloride-methanol
11. customThe appropriate fraction was evaporated
12. customthe product crystallized from methanol
13. customRecrystallization from methanol