Patent GB-1012326-A (GB)
Title: New phosphorus-containing isonitriles
IPC: C07F9/12
Filed: 1963-12-17
Abstract: The invention comprises phosphorus containing isonitriles of the general formula:-Rp(NC)m wherein Rp is a phosphorus containing organic radical, being an ester, thiol, thiono or thionothial ester, and/or amide of an acid of 3- or 5-valent phosphorus, m is 1 to 4, and NC is attached to a C atom forming part of the group Rp. Preferred isonitriles are: <FORM:1012326/C2/1> or <FORM:1012326/C2/2> wherein R1, R2 are the same or different, and are alkyl, alkenyl, aryl, alkoxy, alkylamino, dialkylamino or a further -X-A-(NC)m group. X is oxygen or sulphur; Y is oxygen or sulphur; A is a hydrocarbon radical which may be substituted; n is 0 or 1, and m is 1 to 4. The isonitriles may be prepared by reaction of phosphorus containing formamides, of formula Rp(NH-CHO)m with acyl halides in order to split off water, in the presence of a base; the preferred agent is phosgene with a trialkylamine. The reaction is suitably performed in an inert solvent, e.g. hydrocarbons, chlorinated hydrocarbons or ethers; at temperatures of - 10 DEG  to +30 DEG  C. using 0.9-1.1 moles of phosgene with 1.8-3.0 moles of base to 1 mole of formamide. The formamides, which are stated to be novel compounds, may be prepared by reaction of acylating derivatives of acids of 3- or 5-valent phosphorus, with formamides containing -OH, thiol, or amino groups capable of acylation, suitably in inert solvent in presence of a base. Optionally the reaction to give the formamide and the reaction of the formamide with the acyl-halide may be combined into a single continuous reaction.  Examples are given for the preparation of seven isonitriles, and also several examples for preparation of suitable formamides.  The compounds are used as insecticides and, possibly, fungicides, as compositions with inert solid and liquid carriers (see Division A5).ALSO:Pesticidal compositions comprise phosphorus containing isonitriles, of general formula Rp (NC) m. wherein Rp is a phosphorus containing organic radical in which the phosphorus is in the form of an ester, thiol, thiono, or thionothiol ester, and/or amide of an acid of 3- or 5- valent phosphorus, and m is 1-4, and NC is attached to a C atom forming part or the group Rp together with an inert carrier or diluent.  Preferred isonitriles are those of formul :  <FORM:1012326/A5-A6/1> <FORM:1012326/A5-A6/2> wherein m is as above, n is 0 or 1; R1 and R2, which may be the same or different, are alkyl, aryl, alkenyl, alkoxy, alkylamino, or dialkyl-amino, or a further -X-A-(NC)m group; X is oxygen, or sulphur, Y is oxygen or sulphur; and A is a hydrocarbon group which may be substituted, the isonitriles may be used in concentrations of 0.00001%-1% diluted with an inert solid or liquid carrier, as suspensions, dispersions, powders, and dusts.  Solid carriers include talc, chalk, bentonite, and clay; liquid carriers may be water, (optionally with an emulsifier), alcohols, ketones, and liquid hydrocarbons. Examples are given for compositions containing: (1) O, O-diethyl-O-(2-isocyano-2-methyl-1-propyl)-thionophosphate; (2) O,O-dimethyl-O-(3-isocyano-1 propyl)-phosphate; (3) O,O-dimethyl-O-(2-isocyano-ethyl)-thionophosphate together with an equal amount of dimethylformamide and 20% by weight of a benzyl hydroxy polyglycol ether having 10-15 glycol ether groups as an emulsifier.  These compositions are suitably diluted with water. The compositions may contain a mixture of isonitriles, and also be used in combination with other known insecticides, or fertilizers. The isonitriles of the invention are also stated to have fungicidal properties.