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Mild and highly efficient I2 and Et3N aided cyclodeselenization of in situ generated selenosemicarbazide is described to obtain 2-amino-1,3,4-oxadiazole peptidomimetics.

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A stability-indicating gas chromatography (GC) method has been developed and validated for the quantitative determination of divalproex sodium impurities in pharmaceutical preparation. A technique has been developed whereby the peak purity of a compound with poor UV detection can be determined using a gas chromatograph coupled with a mass spectrometer. The drug products were subjected to hydrolysis, oxidation, photolysis, and heat to apply stress conditions. The stability-indicating nature of the method has been proven by establishing peak purity of all stressed samples. The chromatographic separation was performed on a fused silica capillary (Quadrex-FFAP, 30 meter, 0.32 mm and 1 microm film thickness) column. The method validation results indicate that the method is specific, accurate, linear, reproducible, rugged, and robust. The effectiveness of the technique was demonstrated with stability sample analysis of divalproex sodium in its pharmaceutical preparation.

An efficient synthesis of N α -protected amino nitriles from N α -protected amino acid amides employing Ph 3 P, I 2 and NMM was described. Various amino acid amides, protected by Fmoc, Z and Boc were conveniently converted to nitriles in high yields. Side chain protected amino acid amides were well-tolerated and a good yield of products was obtained. The protocol serves as one of the mild, among a few available, methods for the racemization-free conversion of N α -protected amino acid amides to corresponding nitriles with neither harsh condition nor catalyst.

Herein we demonstrate a chemoselective reaction of Nβ‐protected amino alkyl sulfonyl azides with in situ generated Nα‐protected amino acid selenocarboxylates via step wise intramolecular cyclization followed by decomposition to obtain N‐acyl sulfonamide tethered peptidyl conjugates. The protocol offers the synthesis of orthogonally protected N‐acyl sulfonamide tethered peptidomimetics under simple and mild reaction conditions employing commercially available amino acids in presence of NaBH2Se3 as a selenating agent. Also, the synthesis of N‐acyl sulfonamide tethered amino acid and aryl conjugates were accomplished as an extension of the above strategy.

The synthesis of α‐ureidopeptidomimetics employing a simple, mild and straight forward route starting from benzyloxy carbonyl (Cbz‐) protected amino acid esters in presence of 2‐Cl pyridine (2‐chloropyridine) and Tf2O (triflic anhydride) in one‐pot is described. The in situ generated isocyanate intermediates react with amino acid esters to yield the title compounds in good yields (89‐96%) and the protocol proved to be racemization free.

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