Patent GB-497506-A (GB)
Title: Process for the production of n-acylurethanes
IPC: C07C271/06
Filed: 1937-10-29
Abstract: N-acyl urethanes of the general formula <FORM:0497506/IV/1> are prepared by treating urethanes of the formula <FORM:0497506/IV/2> with acylating agents.  R1 in the above formulae represents a substituted or unsubstituted aliphatic or hydroaromatic radical, R2 represents a substituted or unsubstituted alkyl, aralkyl, cycloalkyl or aryl residue.  The term acyl includes the residue of a saturated or unsaturated carboxylic acid which may also contain hetero atoms or hetero atom groupings such as -O-, -S-, <FORM:0497506/IV/3> , and which may be further substituted particularly by water solubilizing groups.  At least one of the groups R1, R2 or acyl must be an aliphatic or alicyclic residue containing more than eight carbon atoms.  The acylation is preferably carried out by treating the urethanes in the presence of heat with fatty acid halides, with or without a solvent such as benzene or toluene.  Acid binding agents such as pyridine or diethylaniline may also be present.  Urethanes suitable as parent materials for the process of this invention include undecyl carbamic acid methyl, ethyl, propyl, butyl, or amyl ester, heptadecyl carbamic acid ethyl or amyl ester, urethanes respectively made from the carboxylic acids of the naturally occurring or hydrogenated fats or oils such as the fatty acids from palm nut oil, coconut oil, soya bean oil, hydrogenated cod liver oil, or resins.  Also naphthenic acid, the carboxylic acids of camphor and fenchone, methyl carbamic acid methyl, butyl, decyl, undecyl dodecyl, octodecyl and oleic esters.  As acylating agents there are mentioned the halides, esters and anhydrides of organic carboxylic acids such as acetic, propionic, butyric, stearic palmitic, phenoxyacetic, phenylaminoacetic, and phenylthioacetic acid, dodecylthioacetic acid, octylthiopropionic acid and benzoic acid.  Water solubility of the compounds is produced by the introduction of the SO3H-group.  In examples: (1) undecylcarbamic acid methyl ester, made by decomposing undecylamine with chlorocarbonic acid methyl ester, is dissolved in toluene and treated with phenoxyacetic acid chloride during the course of 12 hours.  After evaporation to dryness, finally under reduced pressure, N-phenoxyaceto-N-undecyl carbamic acid methyl ester is obtained.  This may be converted into a water soluble product by treatment first with 100 per cent sulphuric acid and then with oleum. Instead of the undecylcarbamic acid methyl ester above, there may be used heptadecylcarbamic acid ethyl ester, and undecyl-carbamic acid butyl ester and as acid chlorides, butyric acid chloride and propionic acid chloride; (2) phenyl-thioacetic acid chloride is allowed to react with the high molecular alkyl carbamic acid methyl ester containing the radicals corresponding to the alcohols made by hydrogenation of fish oil to give the corresponding N-phenylthioaceto derivative; (3) a toluene solution of undecyl carbamic acid methyl ester is treated with sulphoacetic acid chloride and the product worked up as in example (1).  Other fatty acid chlorides may also be used such as oleic acid chloride. Specification 497,572 is referred to.