2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 22875684, compound

Participants

Reaction Steps

To a solution of 7β-methyl-5α-4-azapregnane-3,20-dione (5.5 gm, 16.6 mmol) in dry toulene (100 mL) was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 4.52 gm, 19.92 mmol) followed by bis(trimethylsilyl)trifluoroacetamide (17.6 mL, 66.4 mmol) and triflic acid (0.11 mL, 1.3 mmol). The mixture was stirred under nitrogen for 24 hr at room temperature after which methyl acetoacetate (1.8 mL, 1.66 mmol) was added and stirring continued for 4 hr followed refluxing for 48 hr. The reaction mixture was poured into water (500 mL) containing sodium bicarbonate (8 gm) and sodium sulfite (3 gm). The solution was extracted with methylene chloride (3×250 mL), washed with water, saturated salt solution, and dried over anhydrous sodium sulfate. The solvent was removed by rotoevaporation and the product purified by flash column chromatography on silica gel eluted with 10% isopropanol in hexane as eluent to the title compound (2.47 gm).

Provenance & Evidence