Patent ID: 8354544

Claim:
A process for the preparation of 1-benzyl-3-hydroxymethyl-1H-indazole represented by the following formula (II): in which R 1 and R 2 , which may be the same or different, are hydrogen or an alkyl group having from 1 to 6 carbon atoms, R 3 , R 4 and R 8 , which may be the same or different, may be hydrogen, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a halogen atom, R 5 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, or together with R 6 and R 7 may form a ring having 5 or 6 carbon atoms, and R 6 and R 7 , which may be the same or different, may be hydrogen, an alkyl group having 1 to 5 carbon atoms, or one of R 6 and R 7 together with R 5 may form a ring having 5 or 6 carbon atoms, in which a) a 1-benzyl-3-halogeno-1H-indazole of formula (III): in which X is a halogen atom selected from iodine and bromine, is caused to react with an alkyl magnesium halide of formula RMgX′ where R is an alkyl group having 1 to 6 carbon atoms and X′ is a halogen atom selected from bromine and chlorine, preferably chlorine, to form intermediate compound (IV): b) the said intermediate compound (IV) is caused to react with a carbonyl compound of formula R 1 —CO—R 2 to form a compound of formula (II), or alternatively to b) b′) the said intermediate compound (IV) is caused to react with an amide of formula R′R″N—CO—R 1 , where R′ and R″, which may be the same or different, are an alkyl group having 1 to 3 carbon atoms, to form an intermediate compound (VIII): which is caused to react with a carbonyl group reducing agent to form a compound of formula (II).