反应详情

温度

60 °C

To a stirred mixture of 0.23 g of g of cis-(4-hydroxy-cyclohexyl)-carbamic acid tert-butyl ester, 0.54 g of 1.1′-(azodicarbonyl)-dipiperidine and 20 mL of benzene was added 0.4 g of tri-n-butyl-phosphine and 1.3 g (8 equivalents) of 2,2-difluoro-2-phenyl-ethanol. The mixture was heated to 60° C. overnight, then an additional 0.5 g of 1.1′-(azodicarbonyl)-dipiperidine and 0.4 g of tri-n-butyl-phosphine was added and heating continued for another 24 h. The mixture was cooled, diluted with 25 mL of toluene, filtered and the filter pad washed with 5 mL of toluene. The filtrate was purified by chromatography on silica gel eluting with a gradient of 0%-20% ethyl acetate in hexane gave 0.15 g of product as a resin: 1H NMR (400 MHz, CDCl3) 7.5 (m, 5H), 3.95 (m, 2H), 3.4 (m, 1H), 1.95 (m, 2H), 1.6 (m, 6H), 1.45 (s, 9H).

1. temperatureheating
2. temperatureThe mixture was cooled
3. filtrationfiltered
4. washthe filter pad washed with 5 mL of toluene
5. customThe filtrate was purified by chromatography on silica gel eluting with a gradient of 0%-20% ethyl acetate in hexane