Phosphorus anhydrides synthesis

Third, the synthesis of phosphorus anhydrides is the final step toward... 

As previously noted (Introduction) a number of metal-containing polyesters have been synthesized employing organometallic dihalides and salts of dicarboxylic acids. Further the synthesis of phosphorus-containing polyesters and polyamides has also been accomplished (for instance 11-15). Previous attempts by our group to synthesize the analogous phosphorus anhydrides failed. 

G. Centi, F. Trifiro, J. R. Ebner, and V. M. Franchetti, Medianistic aspects of maleic anhydride synthesis from C4 hydrocarbons over phosphorus vanadium oxide. Chemical Reviews, vol. 88, pp. 55-80,1988. 

Centi, G., Trifiro, F., Ebner, J., etal. (1988). Mechanistic Aspects of Maleic Anhydride Synthesis from C4 Hydrocarbons over Phosphorus Vanadium Oxide, Chem. Rev., 88, pp. 55-80. 

Centi G., Manenti I., Riva A. and Trifiro F. (1984). The ehemistry of catalysts based on vanadium-phosphorus oxides Note HI Catalytic hehaviour of different phases in 1-butene oxidation to maleic anhydride, AppL Catal., 9, pp. 177-190 Centi G., Trifiro F., Ebner J.R. and Franchetti V.M. (1988). Mechanistie aspects of maleic anhydride synthesis from C4 hydrocarbons over phosphorus vanadium oxide, Chem. Rev., 88, pp. 55-80. 

These formulae explain the scission products of the two alkaloids and the conversion of evodiamine into rutaecarpine, and were accepted by Asahina. A partial synthesis of rutaecarpine was effected by Asahina, Irie and Ohta, who prepared the o-nitrobenzoyl derivative of 3-)3-amino-ethylindole-2-carboxylic acid, and reduced this to the corresponding amine (partial formula I), which on warming with phosphorus oxychloride in carbon tetrachloride solution furnished rutaecarpine. This synthesis was completed in 1928 by the same authors by the preparation of 3-)S-amino-ethylindole-2-carboxylic acid by the action of alcoholic potassium hydroxide on 2-keto-2 3 4 5-tetrahydro-3-carboline. An equally simple synthesis was effected almost simultaneously by Asahina, Manske and Robinson, who condensed methyl anthranilate with 2-keto-2 3 4 5-tetrahydro-3-carboline (for notation, see p. 492) by the use of phosphorus trichloride (see partial formulae II). Ohta has also synthesised rutaecarpine by heating a mixture of 2-keto-2 3 4 5-tetrahydrocarboline with isatoic anhydride at 195° for 20 minutes. 

Phosphine(s), chirality of, 314 Phosphite, DNA synthesis and, 1115 oxidation of, 1116 Phospholipid, 1066-1067 classification of, 1066 Phosphopantetheine, coenzyme A from. 817 structure of, 1127 Phosphoramidite, DNA synthesis and, 1115 Phosphoranc, 720 Phosphoric acid, pKa of, 51 Phosphoric acid anhydride, 1127 Phosphorus, hybridization of, 20 Phosphorus oxychloride, alcohol dehydration with. 620-622 Phosphorus tribromide, reaction with alcohols. 344. 618 Photochemical reaction, 1181 Photolithography, 505-506 resists for, 505-506 Photon, 419 energy- of. 420 Photosynthesis, 973-974 Phthalic acid, structure of, 753 Phthalimide, Gabriel amine synthesis and, 929... 

By Dehydration of a-Diketone Hydrazone Oximes Another general method of synthesis of 2i/-triazoles involves intramolecular elimination of water from adjacent hydrazone and oxime functions (Scheme 32). The usual reagent is acetic anhydride, but others, including phosphorus pentachloride and urea, have been used. 

Ochiai, who reported in 1936 the first synthesis of the imidazo[2,l-h]thia-zole system (36CB1650), transformed ethyl 2-mercapto-5-methyl-imidaz-oIe-4-carboxylate with monochloroacetone into 2-(acylalkylthio)-imidazole 36. Refluxing 36 in phosphorus oxychloride yields ethyl 3,5-dimethylim-idazo[2,l-h]thiazole-6-carboxylate. No cyclization could be achieved by heating 36 in acetic anhydride because N-acylation (to 37) inhibited further reaction to the bicyclic system. 

Preparation of oxazole Cyclocondensation of amides, through dehydration, leads to the formation of corresponding oxazoles. This synthesis is known as Robinson-Gabriel synthesis. A number of acids or acid anhydrides, e.g. phosphoric acid, phosphorus oxychloride, phosgene and thionyl chloride, can bring about this dehydration. 

M-Caproic anhydride has been prepared by heating caproic acid with acetic anhydride,3 by heating sodium caproate and acetic anhydride in a sealed tube,4 by the action of phosphorus oxychloride on barium caproate,6 by the action of acetyl chloride on caproic acid,6 and by treating a mixture of sodium caproate and sulfur with chlorine.7 The method used in the present synthesis was first described by Hurd and Dull.8... 

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