反应详情

7-Methylene-1,5-dithiacyclooctan-3-ol (C-8 Alcohol; 2.9 g, 16 mmole) and dibutyl tin dilaurate (10 mg; Sigma-Aldrich) were dissolved in dry tetrahydrofuran (THF, 10 ml) under nitrogen. The resulting solution was heated to reflux and a solution of 2,4,4-trimethyl-1,6-diisocyanatohexane (1.76 g, 8.2 mmole) in dry THF (10 ml) was added dropwise. The reaction was monitored by thin layer chromatography (ether:methylene chloride 1:1) until the starting C8-Alcohol was consumed. (About 12 hours reaction time.) The solvent was then evaporated to give a viscous clear oil/gum. The oil/gum was purified by dissolving in methanol (15 ml per gram) to give a slightly milky solution. A small quantity of the gum separated. The solution was filtered into another flask and water (3 ml per gram) was added slowly to the filtrate with stirring. During the addition, a white residual material separated from the solution. The liquid solvent was decanted and the residue was washed with methanol:water 3.5:1. The washed residue was dissolved in methylene chloride, BHT inhibitor was added (1 mg per gram), and the solution dried with sodium sulfate. The solvent was evaporated to give a slightly cloudy viscous liquid (4.36 g, 96% yield). The product structure of C-8 Diurethane was confirmed by 1H and 13C NMR.

1. temperatureThe resulting solution was heated
2. temperatureto reflux
3. customwas consumed
4. custom(About 12 hours reaction time.) The solvent
5. customwas then evaporated
6. customto give a viscous clear oil/gum
7. customThe oil/gum was purified
8. dissolutionby dissolving in methanol (15 ml per gram)
9. customto give a slightly milky solution
10. customA small quantity of the gum separated
11. filtrationThe solution was filtered into another flask
12. additionwater (3 ml per gram) was added slowly to the filtrate
13. additionDuring the addition
14. customa white residual material separated from the solution
15. customThe liquid solvent was decanted
16. washthe residue was washed with methanol:water 3.5:1
17. dissolutionThe washed residue was dissolved in methylene chloride
18. additionBHT inhibitor was added (1 mg per gram)
19. dry with materialthe solution dried with sodium sulfate
20. customThe solvent was evaporated