1,2-Dihydro Dexamethasone synthesis

Yield:-

Reaction Conditions:

with hydrogen;Wilkinson's catalyst in ethanol;ethyl acetate at 20; under 760.051 Torr; for 336 h;

Steps:

Intermediate 1(8S,9R,10S,11S,13S,14S,16R,17R)-9-Fluoro-11,17-dihydroxy-17-(2-hydroxyacetyl)-10,13,16-trimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3(2H)-one In a 1000 mL round-bottomed flask was suspended dexamethasone (10 g, 25.48 mmol) in EtOAc (400 mL) and ethanol (100 mL) and tris(triphenylphosphine)rhodium(I)chloride (Wilkinson's catalyst, 2.5 g, 2.70 mmol) was added together with a magnetic stirrer bar. The mixture was vigorously stirred in a hydrogen atmosphere (1 atm) at room temperature for 1 week and another 1.0 g of the catalyst was added. The reaction was allowed to proceed for another week and the resulting mixture was concentrated in vacuo to obtain a solid that was suspended in DCM (100 ml) and the suspension was filtered. The obtained solid was washed with 3 portions of DCM (50 ml) and dried on the sinter in air, yielding 9.6 g of the target compound as an off white solid. APCI-MS m/z: 395 [MH⁺].

References:

ASTRAZENECA R&D US2010/256103, 2010, A1 Location in patent:Page/Page column 14-15