Patent GB-743940-A (GB)
Title: Process for producing isonitrones
IPC: C07D273/00
Filed: 1953-07-09
Abstract: The invention comprises isonitrones which are compounds containing the group <FORM:0743940/IV(a)/1> They may be prepared by reacting an aldimine or ketimine with a per-compound or by reacting a mixture of an aldehyde or ketone and a primary amine, or a salt thereof, with a percompound.  They may also be formed by reacting primary amines with per-compounds, in which case intermediates aldehydes or ketones are possibly formed. Suitable percompounds are hydrogen peroxide, Caro's acid, organic per-acids, e.g. peroxyformic acid, peroxyacetic acid, peroxypropionic acid, peroxybutyric acid, peroxybenzoic acid and monoperoxyphthalic acid, as well as mixtures of hydrogen peroxide with organic acids.  Aldimines and ketimines suitable as starting materials include the condensation products of aliphatic aldehydes, succinic dialdehyde, cyclohexyl formaldehyde, phenylacetaldehyde, benzaldehyde, chlorbenzaldehydes, nitrobenzaldehydes, a b -naphthaldehyde and furfural; or of aliphatic ketones, acetophenone, chloroacetophenones, cyclopentanone, and cyclohexanones, with aliphatic primary amines, ethylene diamine, hexamethylene diamine, aminocaproic acid, cyclopentylamine, benzylamine, aniline, toluidines and chloroanilines.  The isonitrones may be converted into amides. In the examples: (a) ethylidene isobutylamine is reacted with peracetic acid to give methyl-N-isobutyl isonitrone <FORM:0743940/IV(a)/2> (b) n-butyraldehyde is mixed with isopropylamine and reacted with peracetic acid to give n-propyl 1-N-isopropyl isonitrone <FORM:0743940/IV(a)/3> (c) cyclohexylamine is mixed with n-butyraldehyde and the resulting mixture reacted with peracetic acid to give n-propyl-N-cyclohexyl isonitrone <FORM:0743940/IV(a)/4> which is heated to give N-cyclohexyl-n-butyramine; (d) isopropylamine is mixed with acetone and the mixture reacted with peracetic acid to give dimethyl-N-isopropyl isonitrone <FORM:0743940/IV(a)/5> (e) cyclopentylidene-cyclohexylamine is reacted with peracetic acid to give tetramethylene-N-cyclohexyl-isonitrone <FORM:0743940/IV(a)/6> (f) cyclohexylidene-cyclohexylamine is reacted with peracetic acid to give pentamethylene-N-cyclohexylisonitrone <FORM:0743940/IV(a)/7> the product is heated and forms N-cyclohexyl-caprolactam; (g) cyclohexanone is mixed with cyclohexylaminoacetate and reacted with peracetic acid to give pentamethylene-N-cyclohexyl-isonitrone; (h) cyclohexylidene-isobutylamine are reacted with peracetic acid to give pentamethylene-N-isobutyl-isonitrone <FORM:0743940/IV(a)/8> (j) ethylene diamine is mixed with cyclohexamone and the resulting mixture reacted with peracetic acid to give di-pentamethylene-N,N1-ethylene-di-isonitrone <FORM:0743940/IV(a)/9> (k) cyclopentylidene-aniline is reacted with peracetic acid to give tetramethylene-N-phenyl-isonitrone which on neutralizing with potassium carbonate and heating gives N-phenyl-piperidine-2; (b) cyclohexylidene aniline is reacted with peracetic acid to give pentamethylene-N-phenyl-isonitrone <FORM:0743940/IV(a)/100> which on heating gives N-phenyl-caprolactam; (m) cyclohexylidine-p-chloroaniline is reacted with peracetic acid to give pentamethylene-N-(p-chlorophenyl)-isonitrone <FORM:0743940/IV(a)/111> which on heating gives N-(p-chlorophenyl)-caprolactam; (n) benzylidene methyl-amine is reacted with perbutyric acid to give phenyl-N-methylisonitrone <FORM:0743940/IV(a)/122> (o) a  - methyl - benzylidine - cyclohexylamine is reacted with peracetic acid to give methyl-phenyl-N-cyclohexyl-isonitrone <FORM:0743940/IV(a)/133> and (p) furfurylidine-methylamine is reacted with peracetic acid to give a -furyl-N-methyl isonitrone <FORM:0743940/IV(a)/144>