Industrial process for the synthesis of 17alpha-acetoxy-11beta-[4-(N,N-dimethyl-amino)- phenyl]-19-norpregna-4,9-diene-3,20-dione and new intermediates of the process

The present invention relates to a new industrial process for the synthesis of solvate- free 17α-acetoxy-11 -[4-(N,N-dimethyl-amino)-phenyl]-19-norpregna-4,9-diene-3,20-dione [CDB -2914] of formula (I) which is a strong antiprogestogene and antiglucocorticoid agent. The invention also relates to compounds of formula (VII) and (VIII) used as intermediates in the process. The process according to the invention is the following: i) 3-(ethylene-dioxy)-estra-5(10),9(11)-diene-17-one of formula (X) is reacted with potassium acetilyde formed in dry tetrahydrofuran by known method, ii) the obtained 3-(ethylene-dioxy)-17α-ethynyl-17 -hydroxy-estra-5(10),9(11)-diene of formula (IX) is reacted with phenylsulfenyl chloride in dichloromethane in the presence of triethylamine and acetic acid, iii) the obtained isomeric mixture of 3-(ethylene-dioxy)-21-(phenyl-sulfinyl)-19-norpregna-5(10),9(11),17(20),20-tetraene of formula (VIII) is reacted first with sodium methoxide in methanol, then with trimethyl phosphite, iv) the obtained 3-(ethylene-dioxy)-17α-hydroxy-20-methoxy-19-norpregna-5(10),9(11),20-triene of formula (VII) is reacted with hydrogen chloride in methanol, then v) the obtained 3-(ethylene-dioxy)-17α-hydroxy-19-norpregna-5(10),9(11l)-diene-20- one of formula (VI) is reacted with ethylene glycol hi dichloromethane in the presence of trimethyl orthoformate and p-toluenesulfonic acid by known method, vi) the obtained 3,3,20,20-bis(ethylene-dioxy)-17α-hydroxy-19-norpregna- 5(10),9(11)-diene of formula (V) is reacted with hydrogen peroxide in a mixture of pyridine and dichloromethane in the presence of hexachloroacetone by known method, vii) the obtained 3,3,20,20-bis(ethylene-dioxy)-17α-hydroxy-5,10-epoxy-19-norpregn-9(11)-ene of formula (IV), containing approximately a 1:1 mixture of 5α,10α- and 5 ,10 -epoxides, is isolated from the solution and reacted with a Grignard reagent obtained from 4-bromo-N,N-dimethyl-aniline in tetrahydrofuran in the presence of copper(I) chloride catalyst without separation of the isomers by known method, viii) the obtained 3,3,20,20-bis(ethylene-dioxy)-5α,17α-dihydroxy-11 -[4-(N,N-dimethylamino)-phenyl]-19-norpregn-9(11)-ene of formula (III) is reacted with potassium hydrogensulfate in water by known method, ix) the obtained 11 -[4-(N,N-dimethylamino)-phenyl]-17α-hydroxy-19-norpregn-4,9-diene-3,20-dione of formula (II) is acetylated with acetic anhydride in the presence of perchloric acid by known method, finally x) the solvate-free c