Diphenyl phosphorazide , Yamada

The procedure described is essentially that of Shioiri and Yamada. Diphenyl phosphorazidate is a useful and versatile reagent in organic synthesis. It has been used for racemlzatlon-free peptide syntheses, thiol ester synthesis, a modified Curtius reaction, an esterification of a-substituted carboxylic acld, formation of diketoplperazines, alkyl azide synthesis, phosphorylation of alcohols and amines,and polymerization of amino acids and peptides. - Furthermore, diphenyl phosphorazidate acts as a nitrene source and as a 1,3-dipole.An example in the ring contraction of cyclic ketones to form cycloalkanecarboxylic acids is presented in the next procedure, this volume. 

Shioiri, T. Yamada, S. Chem. Pharm. Bull. 1974, 22, 849. No spectral and/or analytical data appear to have been reported for diphenyl phosphorazidate. The checkers recorded the following spectral data H) NMR (CDC13), 6 7.0-7.3 (br, s, CgH5-) IR (neat) cm 1 3060 (w, C-H),... 

Yamada S, Ikota N, Shioiri T. Diphenyl phosphorazidate (DPPA) and diethyl phosphorocyanidate (DEPC). Two new reagents for solid-phase peptide synthesis and their application to the synthesis of porcine motilin. J. Am. Chem. Soc. 1975 97 7174-7175. 

Ikota N, Shioiri T, Yamada S, Tachibana S. Amino acids and peptides. XXXI. Phosphorus in organic synthesis. XVIII. Synthesis of porcine motilin by the solid-phase method us- 41. ing diphenyl phosphorazidate (DPPA) and diethyl phosphoro-cyanidate (DEPC). Chem. Pharm. Bull. 1980 28 3347-5336. 

A mixture of 4-ethylenedioxypentanoic acid, diphenyl phosphorazidate, and tri-ethylamine stirred and refluxed 0.75 hr., benzyl alcohol added, and refluxing resumed for 18 hrs. benzyl N-(3-ethylenedioxybutyl)carbamate. Y 83%. F. e. s. K. Ninomiya, T. Shioiri, and S. Yamada, Tetrahedron 30, 2151 (1974) Chem. Pharm. Bull. 22, 1398 (1974). 

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