反应详情

2.6 ml of AcOH and then 0.09 ml of acetaldehyde and 0.038 g of sodium cyanoborohydride are added at RT to a solution of 0.830 g of the compound obtained in EXAMPLE 106 in 22 ml of MeOH. After stirring for 4 hours at RT, 2 drops of concentrated HCl are added and the reaction mixture is then neutralized by the addition of a 5% solution of potassium carbonate. The solvent is concentrated under vacuum, the residue is extracted with AcOEt, the organic phase is washed with water and with a saturated solution of sodium chloride and dried over sodium sulfate and the solvent is evaporated off under vacuum. The residue is chromatographed on silica using a DCM/hexane mixture (80/20; v/v) and then DCM as the eluent to give 0.396 g of the expected product after crystallization from a DCM/iso ether mixture. M.p.=192°-196° C.

1. concentrationThe solvent is concentrated under vacuum
2. extractionthe residue is extracted with AcOEt
3. washthe organic phase is washed with water and with a saturated solution of sodium chloride
4. dry with materialdried over sodium sulfate
5. customthe solvent is evaporated off under vacuum
6. customThe residue is chromatographed on silica using a DCM/hexane mixture (80/20; v/v)