GB423735A - Improvements in methods of manufacturing unsymmetrically substituted alkylene diamines - Google Patents

Abstract

Unsymmetrically substituted ethylene-diamines are manufactured by reducing nitriles of the formula <FORM:0423735/IV/1> where R, R<1>, R<11> and R<111> may be hydrogen or an alkyl, aryl, furfuryl, aralkyl or alicyclic group, or R and R<1> may be combined to form a polymethylene group, but R and R<1> are never both hydrogen simultaneously, the reduction being effected with hydrogen under pressure in the presence of a hydrogenation catalyst, e.g. at 90--140 atmospheres in the presence of reduced nickel on kieselguhr. The nitriles may be prepared by reacting an aldehyde or ketone with a metal cyanide in the presence of a mineral acid and reacting the product with an amine; or by reacting an aldehyde or ketone with an alkali metal bisulphite, reacting the bisulphite compound with an amine and finally reacting the product with a cyanide. The diamines may be employed as accelerators in the vulcanization of rubber. In examples: (1) formaldehyde is treated with sodium metabisulphite and the product is reacted with o-toluidine and then with sodium cyanide to produce o-toluidinoacetonitrile, which is hydrogenated to o-tolylethylenediamine; (2) formaldehyde is treated with sodium metasulphite and the product is reacted with aniline and then with sodium cyanide to yield phenylaminoacetonitrile, which is hydrogenated to phenylethylenediamine; p-tolylaminoacetonitrile similarly yields p-tolylethylenediamine. The foregoing products are identified by conversion into their dibenzoyl derivatives. The two former are employed as accelerators in the vulcanization of pale cr<\>epe rubber in a mix containing also zinc oxide, sulphur and stearic acid, the properties of the products being shown in a table. Starting materials may also be prepared from the following compounds, aldehydes: acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, caproic aldehyde, heptaldehyde, cuminol, furfurol, crotonaldehyde, cinnamic aldehyde and benzaldehyde; ketones: acetone, methyl ethyl ketone, acetophenone, cyclohexanone and benzophenone; amines: xylidine, a - and b -naphthylamine, tetrahydroquinoline, decahydroquinoline, diphenylamine, ditolylamine, dixylylamine, methylaniline, ethylaniline, butylaniline, isopropylaniline, phenyl-a -and b -naphthylamine, methylamine, ethylamine, butylamine, pipecolines, cyclohexylamine, piperidine, dimethylamine, dibutylamine, dicyclohexylamine, benzylamine and dibenzylamine. Specifications 173,063, [Class 2 (iii)], and 371,023 are referred to.ALSO:Unsymmetrically substituted ethylenediamines are manufactured by the action of hydrogen under pressure in the presence of a hydrogenation catalyst on nitriles of the formula <FORM:0423735/III/1> where R, R<1>, R<11> and R<111> may be hydrogen or an alkyl, aryl, furfuryl, aralkyl or alicyclic group, or R and R<1> may be combined to form a polymethylene group, but R and R<1> are never both hydrogen simultaneously. The hydrogenation may be carried out at 90--140 atmospheres in the presence of reduced nickel or kieselguhr. In examples, o-tolyl- and phenylaminoacetonitrile are reduced to o-tolyl- and phenylethylenediamine respectively. The reduction of p-tolylaminoacetonitrile to p-tolylethylenediamine is also referred to. Specification 371,023 is referred to.ALSO:As vulcanization accelerators may be employed unsymmetrically substituted ethylenediamines of the formula <FORM:0423735/V/1> where R, R1, R11 R111 may be hydrogen or an alkyl, aryl, furfuryl, aralkyl or alicyclic group, or R and R1 may be combined to form a polymethylene group, but R and R1 are never both hydrogen simultaneously. A table shows the properties of the products obtained by vulcanizing pale cr<\>zepe rubber in a mix containing zinc oxide, sulphur and stearic acid, using as accelerators (a) o-tolylethylenediamine, and (b) phenylethylenediamine. Specification 371,023, [Group IV], is referred to.