Patent GB-919913-A (GB)
Title: O-heterocyclic phosphoramidate and phosphoramidothioate esters and their production
IPC: C07F9/6509
Filed: 1961-01-23
Abstract: The invention comprises compounds of the formula: R.O.P(:X)(Z)(OY) wherein Y is C1-C5 alkyl, X is oxygen or sulphur, Z is amino or C1-C5 mono- or dialkylamino, and R is 5-pyrazolyl or substituted 5-pyrazolyl radical in which the substituent is selected from C1-C5 alkyl, C1-C5 alkenyl, or phenyl.  They may be obtained by an esterification and/or amidation reaction in which the 5-pyrazolyl or substituted pyrazolyl radical is introduced into an appropriate compound containing the phosphorus nucleus before, during or after the introduction of the alkylester and/or the amino or alkylamino group.  Suitable methods are:- (1) reacting an alkali metal salt of a suitable 5-pyrazolol (ROH) with an O-C1-C5 alkyl phosphoramidochloridate of the formula Cl.P(:X)(OY)Z the reaction being suitably effected in an inert organic solvent and at from 0 to 120 DEG C.; (2) reacting an alkali metal salt of a 5-pyrazolol (ROH) with a C1-C5 alkyl phosphorodichloridate Y.O.P(:X)(Cl)(Cl) to form an intermediate compound of the formula R.O.P(:X)(OY)Cl and then reacting the latter with ammonia or a C1-C5 alkyl amine to produce the desired product.  In the first step of reaction (2) the reactants are preferably employed in substantially equimolecular proportions and preferably at a temperature of from -40 DEG  to 50 DEG C. and advantageously in the presence of a solvent such as benzene or methyl isobutyl ketone.  In the second step the ammonia or C1-C5 alkyl amine is preferably added in a molecular proportion of 2 : 1 to the intermediate dissolved in an organic solvent at from -20 to 80 DEG C. Several examples are given. The products have pesticidal and herbicidal properties (see Group VI).  The alkali metal salts of the 5-pyrazolols used as starting materials may be obtained by reacting an alkali metal hydroxide such as sodium or potassium hydroxide with the corresponding 2-pyrazolin-5-one in a solvent such as benzene at from 35 DEG  to 100 DEG C.  The 2-pyrazolin-5-one compounds used to form the alkali metal salts of the 5-pyrazolols may be obtained by reacting hydrazine or an appropriately substituted hydrazine with a C1-C4 alkyl ester of a suitable acylcarboxylic acid, e.g. formyl acetic acid, aceto acetic acid, propionyl acetic acid, hexanoyl acetic acid, 2-formyl propionic acid, 2-aceto-4-pentenoic acid, 2-(3-butenoyl)-acetic acid, benzoyl acetic acid, 2-furanyl phenyl acetic acid or 2-acetophenyl acetic acid, the reaction being carried out in water as reaction medium and suitably at from 20 DEG  to 80 DEG C.ALSO:A herbicidal or parasiticidal composition comprises as active ingredient a compound of the formula R.O.P(: X)(Z)(O.Y) wherein Y is C1-C5 alkyl, X is oxygen or sulphur, Z is amino or mono- or di-C1-C5 alkylamino, and R is 5-pyrazolyl or a substituted 5-pyrazolyl radical in which the substituents are selected from C1-C5 alkyl, C1-C5 alkenyl, or phenyl (see Group IV (b)).  The composition may be in the form of a dust or of an aqueous suspension containing a wetting agent or may be in the form of an oil-in-water emulsion which may contain a wetting, dispersing, or emulsifying agent.