Diphenyl phosphoryl azide

Carboxylic acids can also be activated by the formation of mixed anhydrides with various phosphoric acid derivatives. Diphenyl phosphoryl azide, for example, is an effective reagent for conversion of amines to amides.140 The proposed mechanism involves formation of the acyl azide as a reactive intermediate. 

The reaction can also be carried out on the acid using diphenyl phosphoryl azide.179... 

A different type of modification in Region E was achieved [223, 224] in the form of the MTX analogue (VI.8) and the folic acid analogue (VI. 10), in which NH is inserted between the phenyl and CONH moiety. For the synthesis of (VI.8), 4-amino-4-deoxy-V °-methylpteroic acid was treated with diphenyl-phosphoryl azide in DMSO, the resultant azide ((VI. 12), 87% yield) was photolyzed in DMF solution in the presence of dimethyl L-glutamate to obtain dimethyl ester (VI.9) (51% yield), and (VI.9) was hydrolyzed with 0.1 M... 

Quinolizidine alcohols and amines react as nucleophiles in the expected way, yielding amides and esters. They can also take part in Mitsunobu-type chemistry, and thus conversion of equatorial hydroxyquinolizidines (157) to axial azides (158) has been accomplished by treatment with triphenyl phosphine, diethyl azodicarboxylates, and diphenyl phosphoryl azide (Equation (16)) <77TL1977>. 

DPPA = diphenyl phosphoryl azide (N02)2DPPA = bis(p-nitorphenyl) phosphoryl azide. 

Scheme 4.20 Curtins rearrangement using diphenyl phosphoryl azide.

PA-6 (85)/PA-66 (15) Wayne extruder at 280 °C/diphenyl phosphoryl azide additive/DSC Bhattacharjee and Khanna 1990... 

Diphenyl phosphoryl azide triethylamine Urethans from carboxylic acids Simplified Curtius degradation... 

Diphenyl phosphoryl azide triethylaniine Reactions with diphenyl phosphoryl azide Peptide synthesis by fragment coupling... 

Diphenyl phosphoryl azide in dimethylformamide followed by triethylamine added at or below 0° to a soln. of N-carbobenzoxy-L-leucyl-L-leucine and L-valyl-L-phenylalanine methyl ester hydrochloride in the same solvent, stirred several hrs. at the above temp, and overnight at room temp. -> product. Y 87%. - Practically no racemization occurred. F. e., also direct prepn. of urethans from carboxylic acids (cf. Synth. Meth. 17, 393) by a simplified Curtius degradation, s. T. Shioiri, K. Ninomiya, and S. Yamada, Am. Soc. 94, 6203 (1972) Tetrah. Let. 1973, 2343 synthesis of N-subst. carboxylic acid amides and peptides with diethyl phosphoryl cyanide s. Tetrah. Let. 1973, 1595 coupling reagents in peptide synthesis, review, s. Y. S. Klausner and M. Bodansky, Synthesis 1972, 453 review of peptide synthesis s. J. Meienhofer, Chem. Technol. 3, 242 (1973). 

Sample preparation Mix 100 jaL plasma, 500 p,L water, 560 p.L 100 mM pH 9.3 borate buffer, 10 p.L 100 p,M IS in water, and 420 p,L 762 (xg/mL DBD-F in MeCN, let stand at room temperature for 30 min (to derivatize thiol in metabolites and IS), evaporate the MeCN under reduced pressure, add 2 mL ethyl acetate to the remaining solution, mix vigorously, centrifuge at 3000 rpm for 2 min. Wash the aqueous layer three more times with ethyl acetate. Adjust the pH of the aqueous layer to 1-2 with ca. 1.5 mL 100 mM HCl, extract three times with 2 mL portions of ethyl acetate. Combine the organic layers and evaporate them to dr5Uiess under reduced pressure, reconstitute the residue with 100 xL MeCN. Remove a 50 p.L aliquot, add 5 p.L DPP A, add 45 xL 17.8 mg/mLi -(—)-DBD-Apy in MeCN, let stand at room temperature for 2 h (to derivatize carboxylic acid), inject an aliquot. (DBD-F is 4-()V,IV-dimethylaminosulfonyl)-7-fluoro-2,l,3-benzoxadiazole. i -(—)-DBD-Apy is i -(—)-4-( V,IV-dimethylaminosulfonyl)-7-(3-aminopyrrolidin-l-yl)-2,l,3-benzoxadiazole. DPPA is diphenyl phosphoryl azide. They are all available from Tokyo Kasei or TCI America (www.tciamerica.com).)... 

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