GB851577A - Pyridine compounds and methods for producing the same - Google Patents

Abstract

The invention comprises compounds of the general formula: <FORM:0851577/IV(b)/1> where R1 and R2 are the same or different and represent hydrogen atoms or alkyl C1-4 radicals or R1 and R2 together with - N< represent a pyrrolidino, piperidino, alkyl C1-4 pyrrolidino, di(alkyl C1-4) pyrrolidino or alkyl C1-4 piperidino radical, and acid-addition salts thereof, and the preparation thereof, where R1 and R2 are alkyl radicals or together with N are heterocyclic radicals, by reacting a pyridyl magnesium halide with an appropriate 1-cyano-cyclohexylamine and, where R1 is hydrogen and R2 is alkyl, by reacting a pyridyl alkali-metal compound with an alkyl N-cyclohexylidene amine and, where R1 is hydrogen or alkyl and R2 is alkyl, by alkylating an appropriate primary or secondary 1-pyridylcyclohexylamine for example by reaction with an alkyl ester or a mixture of formic acid and formaldehyde or by the two stage process of acylation and reduction and, where R1 is hydrogen and R2 is alkyl, by reacting an appropriate 1-pyridyl-cyclohexylamine with an aldehyde or ketone and hydrogenating the reaction mixture and, where R1 and R2 are both hydrogen atoms, by hydrolysing an appropriate alkyl N-(1-pyridyl-cyclohexyl)-carbamate or corresponding urea compound or isocyanate and, if desired, converting the products of any of the above processes into their acid-addition salts. The products are central nervous system depressants. Alkyl N-(1-pyridyl-cyclohexyl)-carbamates are prepared from compounds of the general formula: <FORM:0851577/IV(b)/2> where Z is a primary amido group, derived if required by hydrolysis of a nitrile group, by treatment with an alkali-metal hypohalite in the presence of an alkanol or, where Z is a carboxyl group, by treatment successively with hydrazoic acid in strong mineral acid and with an alkanol or by the actions successively of thionyl chloride, an alkali-metal azide and an alkanol or, where Z is a carboxylate ester group, by treatment successively with hydrazine, nitrous acid and an alkanol. 2-[1-(1-acetamido) cyclohexyl] pyridine is prepared by acetylating the corresponding amine. 1-Pyridyl-cyclohexane carboxamides are prepared by hydrolysing 1-pyridyl-cyclohexane carbonitriles which are obtained by condensing pyridine acetonitriles with pentamethylene dibromides.