ethylenedichloride or carbon tetrachloride or aromatic hydrocarbon solvents selected from toluene benzene xylenes etc with or without acid catalysts selected from triflic acid m chlorobenzoic acid peracetic acid trifluoroperacetic acid preferably triflic acid thereafter the deprotection of protected finasteride of formula vi is carried out using acidic or basic conditions preferably carried out under basic conditions using hydrazines alkyl amines selected from methyl amine ethylamine di isopropyl amine the major advantages realized in the present invention includes the protected finasteride of formula vi is obtained in a highly pure form which on further deprotection results in pure finasteride in high yield and low cost with the process of the present invention dihydrofinasteride of formula iv which is an impurity in the finasteride can be removed to less than 0 1 whereas when the finasteride is prepared with the prior art processes this impurity cannot be removed when present in higher quantities the present invention also relates to novel compounds of formula v and formula vi which are used in the preparation of finasteride the details of the process of the invention are provided in the examples given below which are provided by way of illustration only and therefore should not be construed to limit the scope of the invention 4 dimethylamino pyridine 21 3 g 0 17 mol was added to a suspension of dihydrofinasteride 50 g 0 23 mol in toluene 500 ml to this reaction mass benzoyl chloride 24 5.