Patent GB-690385-A (GB)
Title: Improvements in or relating to phosphorus-containing organic compounds
Inventor: POUND DENIS WILLIAM
IPC: C07F9/24
Filed: 1949-12-23
Abstract: Compounds of the general formula <FORM:0690385/IV (b)/1> wherein A represents oxygen or sulphur, X a mono- or di-alkylamino group and Y a mono- or di-alkylamino group or (when A is oxygen) an alkyloxy group (but excluding the case where X and Y are identical dialkylamino groups and A is oxygen), the term "alkyl" including "cycloalkyl" and all the alkyl groups preferably containing not more than 6 carbon atoms, are manufactured by reacting a phosphorus compound PACl3, in the presence of excess of a tertiary alkylamine or a tertiary alkylcycloalkylamine having 6-10 carbon atoms in the molecule, which does not undergo irreversible reaction with the compound PACl3, with an equimolecular proportion each of an anhydrous mono- or di-alkylamine XH and an anhydrous mono- or di-alkylamine or alcohol YH (but not with two molecular proportions of the same dialkylamine when A is oxygen).  The reaction is preferably carried out in the presence also of an inert solvent, which should be capable of keeping in solution at least a substantial amount of the amine hydrochlorides formed as intermediates or by-product. The two reactants (if different) may be added successively (if desired with intermediate isolation of a compound XPACl2 or YPACl2) or in some cases simultaneously.  The tertiary amine or solvent or both may be present initially in full amount or wholly or in part added with or as a solvent for the reacting amine or alcohol, or the tertiary amine may even be added (preferably slowly) at the end of the other additions.  The final reaction mixture usually contains as by-products not only the hydrochloride of the tertiary amine but also compounds such as X2PACl, Y2PACl, X3PA, X2YPA and XPACl2, which are advantageously removed only after the main product XYPACl has been subjected to a further reaction.  If, however, it is desired to isolate the compound XYPACl, this may be effected by removing most of the solvent by distillation, then either (a) adding further tertiary amine or other diluent which is not appreciably a solvent for amine hydrochlorides, and separating the precipitated tertiary amine hydrochloride, or (b) introducing dry ammonia gas in the required quantity at a low temperature to precipitate ammonium chloride, which is immediately separated, and finally in either case subjecting the remaining liquid to fractional distillation.  In examples: (1) ethyl alcohol is stirred with a cooled solution of phosphorus oxychloride in chloroform, after which methyldibutylamine and more chloroform are added, followed by dimethylamine; (2) methyldibutylamine is added to a solution of phosphorus oxychloride in chloroform, and a solution of dimethylamine in ethyl alcohol is then added slowly with stirring; (3) 2 mols. of ethylamine are added to a cooled and agitated solution of 1 mol. of phosphorus oxychloride and excess of methyldibutylamine in chloroform; (4) 2 mols. of dimethylamine are similarly reacted with 1 mol. of thiophosphoryl chloride. Diethylcyclohexylamine is also mentioned as a suitable tertiary amine.  According to the Provisional Specification, the tertiary amine employed may be any one which does not undergo irreversible reaction with the compound PACl3 and which has a basic strength at least as great as that of pyridine.