反应详情

To a stirred solution of 6-hydroxy-nicotinic acid methyl ester (1.67 g, 10.9 mmol) and [5-methyl-3-(tetrahydro-pyran-4-yl)-isoxazol-4-yl]-methanol (2.15 g, 10.9 mmol) in THF (55 mL) at 5° C. under argon was added triphenylphosphine (10.6 g, 39 mmol), then diisopropyl azodicarboxylate (40%, 6.5 mL, 14.2 mmol) was added dropwise. The reaction mixture was warmed to room temperature for 2 h. The reaction mixture was then extracted with tert-butyl methyl ether, and washed with aqueous HCl (2 N) and the organic extract washed with water, dried over sodium sulphate, filtered and evaporated. Purification by chromatography (silica, heptane:ethyl acetate=1:0 to 1:1) afforded the title compound (1.31 g, 36%) as a white solid. MS: m/e=333.2 [M+H]+.

1. extractionThe reaction mixture was then extracted with tert-butyl methyl ether
2. washwashed with aqueous HCl (2 N)
3. extractionthe organic extract
4. washwashed with water
5. dry with materialdried over sodium sulphate
6. filtrationfiltered
7. customevaporated
8. customPurification by chromatography (silica, heptane:ethyl acetate=1:0 to 1:1)