Patent GB-607920-A (GB)
Title: Improvements in or relating to the preparation of tertiary amino aromatic aldehydes
IPC: C07C47/52
Filed: 1946-03-08
Abstract: Tertiary amino aromatic aldehydes are manufactured by reacting an N : N-dialkylformamide (in which the alkyl groups contain from 1 to 5 carbon atoms each), in the presence of a chloride or oxychloride of sulphur or phosphorus, with a tertiary amine in which at least one of the groups attached to the nitrogen atom is a phenyl or 1-naphthyl group unsubstituted in the 4-position or a 2-naphthyl group unsubstituted in the 6-position, whereby aldehyde groups are introduced into the said unsubstituted positions.  The tertiary amine preferably contains at least two phenyl radicals (the remaining valance of the amino group or groups being satisfied by an aliphatic, cycloaliphatic or aromatic hydrocarbon radical), in which case it is advisable to use one molecular proportion of dialkylformamide for each phenyl radical so as to produce a polyaldehyde.  The reaction may be carried out under atmospheric, sub-atmospheric or super-atmospheric pressures, at temperatures of 30-180 DEG  C. or higher, the amine preferably being cooled while the other reactants are added (the dialkylformamide preferably first) and the mixture then slowly heated to complete the reaction.  In examples, the following materials are reacted with dimethyl formamide in the presence of phosphorus oxychloride: (1) N-dimethylaniline, producing p-dimethylaminobenzaldehyde; (2) N-diethylaniline; (3) M-diethyl-o-toluidine; (4) N-diethyl-m - toluidine; (5) o - diethylaminodiphenyl; (6) N-diethyl-a -naphthylamine, yielding 4-diethylamino - 1 - naphthaldehyde; (7) tetraethyl - m - phenylenediamine; (8) N - diethyl - b  - naphthylamine, forming 6-diethylamino-2-naphthaldehyde; (9) N-phenylmorpholine, giving p-N-morpholinobenzaldehyde; (10 (A) N : N1-ethylene - bis - (N - methylphenylamine), producing N : N1-ethylene-bis-methylaminobenzaldehyde); (B) N : N1 - ethylene - bis - ethylaniline; (11) triphenylamine, yielding p : p1 : p11-triformyltriphenylamine; (12) N : N1 - diphenylpiperazine, forming N : N1-(p : p1-diformyldiphenyl)-piperazine; (13) methyldiphenylamine, giving methyldi-(p-formylphenyl)-amine. Additional starting materials specified are, on the one hand, diethyl-, dipropyl- and diamyl-formamide, and, on the other hand, N : N1-dimethyl-N : N1-di-o-tolyl- and -di-a -naphthyl-p-phenylenediamine, N : N1 - diphenyl - N : N1 - dibenzylethylene - diamine, ethyldi-a -naphthylamine, m : m1 : p11-tritolylamine, N : N : N1 : N1 - tetraphenyl - p - phenylenediamine, N : N1-dimethyl-N : N1 : a  : b -tetraphenylethylenediamine, N : N1-bis-cyanomethyl - N : N1 - diphenylethylenediamine, N : N : N1 - triethyl - N1 - phenylethylenediamine, N : N-diethyl-N1-isopropyl-N1-phenylethylenediamine, N : N : N1 - triethyl - N1 - (2 : 5 - xylyl) - ethylenediamine, N : N - di - (hydroxyethyl) - aniline, N : N -dihexyl- and -di-isoamyl-aniline, N : N-di-(b -diethylaminoethyl)-aniline, N : N1-dimethyl-N : N1-diphenylputsescine, methylene-bis - (N : N - dimethylaniline), 3 : 31 - methylene-bis-(6-bromo-N : N-dimethylaniline and N : N-dibenzylaniline.  The phosphorus oxychloride may be replaced by phosphorus trichloride, thionyl chloride, sulphuryl chloride or sulphur dichloride.  N-Diethyl-o-toluidine is obtainable by heating o-toluidine with excess of ethyl iodide in the presence of aqueous potassium carbonate.  N-Diethyl-m-toluidine is obtainable by heating m-toluidine with diethyl sulphate.