Iodine → HCID 56633654, compound

Participants

Reaction Steps

A solution of 10 g. of 6-chloro-17-hydroxy-1α,2α-methylene-4,6-pregnadiene-3,20-dione in 75 ml. of methanol and 75 ml. of tetrahydrofuran is combined with 15 g. of calcium oxide and 500 mg. of azoisobutyronitrile. Several milliliters of a solution of 10 g. of iodine in 50 ml. of tetrahydrofuran and 30 ml. of methanol are added dropwise to the reaction mixture. After an induction time of 60 minutes, the solution loses its color; the residual iodine solution is added dropwise within 8 hours. The reaction mixture is diluted with 500 ml. of dichloromethane, the calcium oxide is filtered off, and the filtrate is washed with sodium thiosulfate solution and water, dried over sodium sulfate, and concentrated under vacuum at 35° C., thus obtaining 13 g. of 6-chloro-17-hydroxy-21-iodo-1α,2α-methylene-4,6-pregnadiene-3,20-dione. This product is dissolved in 130 ml. of acetone and 45 ml. of acetic acid, combined with 69 ml. of triethylamine, and refluxed for 90 minutes. The solution is stirred into ice water. The thus-obtained precipitate is isolated and chromatographed on silica gel. With 16-20% acetone-pentane, 6.1 g. of 21-acetoxy-6-chloro-17-hydroxy-1α,2α-methylene-4,6-pregnadiene-3,20-dione is obtained, m.p. 224° C.

Provenance & Evidence