反应详情

To a solution of the product from step V (5.340 g) in 1,2-dichloroethane (60 mL) is added formaldehyde (1.94 mL of 37% aqueous solution, 23.88 mmol), followed by sodium triacetoxyborohydride (2.403 g, 11.34 mmol) in portions over 20 min. The mixture is stirred at room temperature overnight, then water is added to the mixture, and it is extracted with CH2Cl2. Organic fraction is washed with aqueous NaHCO3 and brine, dried over Na2SO4, concentrated and purified by column chromatography on silica gel eluting with 0-10% of MeOH in CH2Cl2 to give 5-(3,3-dimethyl-but-1-ynyl)-3-[(trans-4-methyl-cyclohexanecarbonyl)-(1-methyl-piperidin-4-yl)-amino]-thiophene-2-carboxylic acid methyl ester.

1. extractionis extracted with CH2Cl2
2. washOrganic fraction is washed with aqueous NaHCO3 and brine
3. dry with materialdried over Na2SO4
4. concentrationconcentrated
5. custompurified by column chromatography on silica gel eluting with 0-10% of MeOH in CH2Cl2