Desoximetasone synthesis

Yield:382-67-2 83%

Reaction Conditions:

Stage #1:dexamethasone with trimethylsilyl iodide in dichloromethane;acetonitrile at -8; for 1 h;
Stage #2: with hydrogenchloride in dichloromethane;water for 2 h;Product distribution / selectivity;

Steps:

3
EXAMPLE 3;Synthesis of Desoximetasone from Dexametasone; [0041] 15 g (38.22 mmol) of Dexamethasone were dissolved in 225 ml of a mixture of Dichloromethane and Acetonitrile (95:5) cooled to -8°C and 16.5 ml of Trimethylsilyl iodide were added. The reaction mixture was stirred for 1 hour at -8°C, and quenched with 30% sodium bisulfite. The Dichloromethane solution was washed with a solution of sodium bicarbonate. A solution of 1 15 ml of Hydrochloric acid (32%) was added to the Dichloromethane solution and the mixture was stirred for 1 hour. The Dichloromethane solution was washed with 1 10 ml of Hydrochloric acid (32%). The Hydrochloric acid solution (225 ml) was then diluted with 200 ml of water, stirred for 1 hour and filtered, followed by the addition of another 250 ml of water to the solution. After 1 hour the mixture was filtered to give 12 g of Desoximetasone (83%).

References:

TARO PHARMACEUTICAL INDUSTRIES LTD.;CHERNIAK, Simon;CYJON, Rosa;OZER, Ilana;NUDELMAN, Igor WO2012/11106, 2012, A1 Location in patent:Page/Page column 15-16

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