反应详情

温度

0 °C

Aqueous 36% formaldehyde solution (205 μl, 2.75 mmol) was added to a methanol (4 ml) solution of 2-tert-butyl-5-methyl-7-(3-methylaminoazetidin-1-yl)-6-phenyl-1,3-benzoxazole-4-carbonitrile (I-73) (103 mg, 275 μmol), followed by cooling at 0° C. Sodium cyanoborohydride (34.6 mg, 550 μmol) and acetic acid (40.9 μl, 715 μmol) were added, followed by stirring at room temperature for 20 minutes. Aqueous 10% sodium carbonate solution and saturated brine were added to the reaction liquid, and this was extracted with ethyl acetate and chloroform. The organic layers were combined, dried over anhydrous magnesium sulfate, concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (chloroform:methanol=200:1), again purified by silica gel column chromatography (dichloromethane:ethyl acetate=1:1) to obtain the entitled compound (94 mg, 88%) as a colorless solid.

1. extractionthis was extracted with ethyl acetate and chloroform
2. dry with materialdried over anhydrous magnesium sulfate
3. concentrationconcentrated under reduced pressure
4. customThe resulting residue was purified by silica gel column chromatography (chloroform:methanol=200:1)
5. customagain purified by silica gel column chromatography (dichloromethane:ethyl acetate=1:1)