3-Heterocyclylalkyl-pyrazoles prodn. - by dehydrogenation or acid elimination from pyrazol(id)ines, useful as CNS depressants

摘要

Title cpds of formula (I): (R1=H, 1-4C alkyl, Ar or COr3; R2=H or 1-4C alkyl; R3=opt. unsatd is not 10C alkyl or aralkyl, aryl (opt. substd by =1 alkyl, amino or MeO but is not 10C in all) NH2, NMe2 or 1-4C alkoxy, n=1-6; Ar=phenyl, opt. with =1 1-4C alkyl or alkoxy, CF3, NO2 and/or halo; E1-E2=CH2N, CH2CH, CH=C or CH2C(OH);) and their pharm.inocuous acid addn. salts are prepd from pyrazol(id)ines of formula (II): (X=H, Cl, Br, I opt. esterified OH; is not 10C alkyl or arylsulphonyl) by HX elimination, then opt. converting free-base to salts or v.v.