Octamethylpyrophosphoramide

Octamethylpyrophosphoramide has been prepared by the action of [(CH3)2N]2P0C1 on [(CH3)2N]20P0C2H5 or 

Caution Octamethylpyrophosphoramide is very toxic (see Properties) and must be handled with great care. All work should be conducted in a vented hood rubber gloves and plastic aprons should be worn by all personnel. Typical symptoms of intoxication from this compound are abdominal cramps and diarrhea. A common symptom of acute intoxication is constriction of the pupils of the eyes. In case of accident leading to possible intoxication, get immediate medical attention. Atropine sulfate is a specific antidote. The checkers make it a practice to soak glassware that has been used for octamethylphosphoramide in a 20 per cent sodium hydroxide solution for 24 hours to destroy residues. 

In a 1-1. three-necked round-bottomed flask equipped with a 50-ml. buret, a 500-ml. graduated dropping funnel, a thermometer, a stirrer, and an exhaust vent protected with a soda-lime drying tube, is placed 378.4 g. (2.22 mols) of bis(dimethylamido)phosphoryl chloride (synthesis 21). In the buret there is placed 20 ml. (1.11 mols) of water, in the graduated dropping funnel is added 232.0 g. (2.30 mols) of triethylamine, and the volume (approximately 320 ml.) is recorded. The contents of the reaction flask are heated to 45 to 50° and then the heater is removed. One milliliter of water is added, followed by one-twentieth (approximately 16 ml.) of the triethylamine. The reaction mixture is stirred until the mildly exothermic reaction subsides (ca. 5 minutes), and the addition of 1 ml. of water followed by 

The crude product has an assay of 99.0% by paper chromatographic analysis. 

Octamethylpyrophosphoramide, when very pure, is a colorless somewhat viscous oil with the following physical constants b.p. 120 to 122° at 0.5 mm. 154° at 2 mm. sp. gr., 1.09. Normally the color is yellow to amber. The compound is miscible with water, soluble in most organic solvents, and insoluble in higher aliphatic hydrocarbons. It is a very toxic substance with a MLD50 to white mice of 17 mg./kg. by intraperitoneal injection. 

One of the most important systemic insecticides is octamethyl-pyrophosphoramide (O.M.P.A. or schradan or pestox III) (I). 

This compound was made by Schrader by the following reaction  

An industrial process worked out by Pest Control Ltd. consisted in a direct synthesis. This general reaction can be represented thus  

The hydrochloric acid is removed by the strong tertiary base, methyldibutylamine, which has a soluble hydrochloride. In B.P. s 631,549 and 652,981 it was shown that compound (II) could be prepared by the action of dimethylamine on POCI3 in chloroform containing an excess of methylbutylamine. The further reaction with water is very conveniently carried out in the same system by adding an excess of aqueous sodium hydroxide solution. The chloroform layer contains the tertiary amine and (I). The solvent and amine are stripped off leaving the product. Side reactions take place, and the commercial product also contains some triphosphoric pentadimethylamide (I A) and smaller amounts of other phosphoric amides. The compound (I A) is itself also a valuable systemic insecticide. 

An important aspect of the use of systemic insecticides is the safety of the crop for human or animal consumption. Systemic 

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Schottky defect See defect structures. Schradan, octamethylpyrophosphoramide,... 

Octamethylpyrophosphoramide is also enzymicahy oxidized in vivo, as well as chemically by permanganate, to a highly effective anti-esterase.5... 

In the course of a study of the decomposition products of radioactive octamethylpyrophosphoramide in white clover (Trifolium repens, strain S100), it was found quite incidentally by Heath and Park,6 that extracts from clover, whether... 

From results of the screening tests conducted at West African Cocoa Research Institute it was found that products containing dimefox were the most satisfactory for the control of P. njalensis. Samples containing the closely similar compound schradan (octamethylpyrophosphoramide) have been found of little or no value. 

Octamethylpyrophosphoramide (ompa) has been shown to loosen ion pairs in solution178 and a 1 3 complex has been isolated with Mg(C104)2. The crystal structure shows that the ligand is bidentate and chelates to the cation through the phosphine oxide oxygens.179... 

Strychnine, which is detoxified by microsomal monooxygenase action, is more toxic to animals on low-protein diets, whereas octamethylpyrophosphoramide, carbon tetrachloride, and heptachlor, which are activated by monooxygenases, are less toxic. Phase II reactions may also be affected by dietary protein levels. Chloramphenicol glu-curonidation is reduced in protein-deficient guinea pigs, although no effect is seen on sulfotransferase activity in protein-deficient rats. 

Nephelauxetic parameter (ft) and SINHA s covalency parameter of (6) for the HMPA-complexes of the lanthanides, and a comparison with other complexes containing P -> O donor ligands. TBP = tributylphosphate, OMPA = octamethylpyrophosphoramide, HMPA = hexamethylpyhosphoramide. To emphasize the weak nephelauxetic effect produced by the P-0 donor ligands, some of the fi and S values are expressed with three or four places after the decimal without rounding off. Ref. [290]. 

OCTAMETHYLPYROPHOSPHORAMIDE see TNK400 PERCHLORIC ACID, SODIUM SALT see PCE750 PERCHLORIC ACID, >50% but not >72% acid, by weight (UN 1873) (DOT) see PCD250... 

TRIS(o-METHYLPHENYL)PHOSPHATE see TM0600 TRIS(2-METHYLPROPYL)ALUMINUM see TKR500 TRIS(NICTINATO)ALUMINUM see AHD650 TRIS(OCTAMETHYLPYROPHOSPHORAMIDE)MANG ANESE(2+), DIPERCHLORATE see TNK400 TRISODIUM ARSENATE, HEPTAHYDRATE see AREOOO... 

Studies of the complex chemistry of the tervalent lanthanides show that coordination numbers higher than six are common, for example in the tetrakistropolonates 79), the complexes of the perchlorates with N,N-dimethylacetamide (DMA) (77) or octamethylpyrophosphoramide 61), of the iodides with N,IV-dimethylformamide (DMF) (76), the nitrates with triphenylphosphine (or arsine) oxide 46), and the -diketone... 

Complexes of Rare Earth Ions with Octamethylpyrophosphoramide... 

TJrevious work in this laboratory (5, 6, 14) has demonstrated the ver-- satility of octamethylpyrophosphoramide (OMPA) as a ligand. Stable complexes of OMPA... 

The rare earth complexes of octamethylpyrophosphoramide are the first examples of isolated complexes with rare earth ions coordinated to the pyrophosphate linkage. Experimental evidence supports the coordination of the phosphoryl oxygens to the metal ion with additional coordination positions occupied by water. 

Triphenyl)aminophosphonium chloride, synthesis 19 (Dimethylamido)phosphoryl dichloride, synthesis 20 Bis(dimethylamido)phosphoryl chloride, synthesis 21 Octamethylpyrophosphoramide, synthesis 22 Methylbromoarsines, sjmthesis 26... 

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