Oxalic Acid → HCID 68132042, compound

Participants

Reaction Steps

To a stirred solution of 5.13 g of 17-ethylenedioxy-11β-hydroxy-3-methoxyestra-1,3,5(10)-triene in 25 ml of dimethylsulfoxide and 25 ml of benzene is added 3 ml of pyridine and 9.3 g of N,N-dicyclohexylcarbodiimide. This mixture is then cooled and 1.5 ml of dichloroacetic acid is added. The whole is next stirred at room temperature for 11/2 hours. It is diluted by the addition of 50 ml of ether and a solution of 4 g of oxalic acid in 10 ml of methanol is added dropwise. The resulting suspension is stirred for 40 minutes at room temperature and then filtered. The filtrate is concentrated to dryness and distributed between methylene chloride and a 10% aqueous solution of sodium bicarbonate. The organic phase is washed with water and dried (Na2SO4) before being evaporated to dryness under reduced pressure. The residue is placed on a column of silica-gel and eluted with chloroform containing various percentages of methanol. The fractions eluted with chloroform containing 5 % of methanol are combined and evaporated to yield a residue which is crystallized from hexane/ether (1:1). Thus is obtained 17-ethylenedioxy-3-methoxyestra-1,3,5(10)-trien-11-one, m.p. 122° - 123° C.

Provenance & Evidence