Verfahren zur Herstellung von cyclischen Diazoverbindungen

摘要

Diaza-cyclo alkane compounds of the formula in which A1 and A2 each represent a direct bond or an alkylene radical containing up to 4 carbon atoms, R represents an organic group, and R1, R2, R3 and R4 each represents a hydrogen atom or an organic group, which comprises treating a compound of the formula in which A1, A2, R, R1, R2, R3 and R4 have the aforesaid meanings, and Hal represents a halogen atom, with an aluminium hydride reducing agent in the presence of an inert organic solvent, decomposing the resulting complex by adding an inorganic base and water, and isolating the desired diaza-cycloalkane compound from the organic solution. The novel compounds of the last general formula above wherein A1 and A2 each represents a direct bond or an alkylene radical containing up to 4 carbon atoms, R represents a phenyl or an alkyl group, R1, R2 and R3 each represents a hydrogen atom or a lower alkyl group, R4 represents a hydrogen atom an Hal represents a halogen atom, are prepared for example by treating a compound of formula R-NH-C(R1)(R2)-A2-C­N, in which A2, R, R1 and R2 have the previouslygiven meanings, with a halogen-aliphatic carboxylic acid halide of the formula Hal0-CO-A1-C(R3)(R4)-Hal, in which A1, R3, R4 and Hal have the previously-given meanings, and Hal0 stands for halogeno, preferably in the presence of a base. By reacting a primary amine of the formula R-NA2, in which R has the previously given meaning with a carbonyl compound of the formula R1(R2)C = O, in which R1 and R2 have the previously given meanings in the presence of hydrogen cyanide or of a metal cyanide, particularly an alkali metal cyanide, a nitrile compound of the formula R-NA-C(R1)(R2)-C­N is formed which may also be prepared by reacting an amine of the formula R-NH2 or an amine, in which the nitrogen is substituted, inaddition to the group R1, by a protective group which prevents di-substitution of a primary amine and is easily removable (for example a benzal group or a carbo-benzoxy group), with a halogeno-aliphatic nitrile of the formula Hal0-C(R1)(R2)-A2-C­N or with an unsaturated aliphatic nitrile, in which the double bond is sufficiently activated by the nitrile group to react with the amine (unsaturated aliphatic nitriles of that type are represented, for example, by acrylonitrile), in the presence of a base, and, if necessary, separating the desired secondary amine compound from any simultaneously formed tertiary amine or removing any easily removable protective group (for example, by mild hydrogenolysis). This latter method yields intermediate nitriles of the formula R-NH-C(R1)(R2)-A2-C­N, in which the group A2 represents an alkylene radical containing up to 4 carbon atoms. 2-Methyl-, 2,2-dimethyl- and 2,5-dimethyl-1-phenyl-4-(N-phenylthiocarbamyl)-piperazines are prepared by reacting the methyl 1-phenyl-piperzines with phenylisocyanate.