Propionic anhydride → HCID 70146704, compound

Participants

Reaction Steps

In a manner analogous to the procedure reported in Baer, H. et al., Can. J. Chem 1991, 69, 1563-1574, 17β-cyclopropyloxy-7β-hydroxy-4-aza-androst-5-en-3-one (1.000 g, 2.895 mmol) from Example 20A or otherwise obtained is dissolved in pyridine (20 mL). Proprionic anhydride (20.0 mL, 156.0 mmol) is added, and the mixture is stirred at room temperature under nitrogen for 12 hours. At the end of the reaction time, the solution is diluted with CH2Cl2 (150 mL) and washed with water (2×100 mL), saturated aqueous NaHCO3 (2×100 mL), water (100 mL) and brine (100 mL). The organic phase is then dried over MgSO4, filtered and evaporated to dryness. The residue is purified by flash chromatography (1:1 EtOAc/CH2Cl2) to give the title compound.

Provenance & Evidence