Condensation of Lactones with Primary Diamines

Abstract

The condensation of dehydroacetic acid and 4-hydroxy-6-methylpyran-2-one with primary diamine derivatives such as hydrazine, 1,2-diaminoethane and 1,6-diaminohexane yielded bispyrone and bispyridone derivatives has been reported. The condensation of 4-hydroxy-6-methylpyran-2-one with hydrazine in acetonitrile generated another bispyrazole product but in n-butanol, this reaction afforded the bispyridones. The structures of the synthesized bispyrazoles were examined by spectroscopy and X-ray diffraction analysis, while those of bispyridones were established by spectroscopy data (NMR, mass). Some new complexes were also synthesized in order to show the behaviour of ligands with suitable crystals for X-ray analysis.

Development of In-Water Scalable Process for the Preparation of [2-(3-Bromo-2-methylphenyl)-7-chloro-1,3-benzoxazol-5-yl]methanol, a Key Intermediate in the Synthesis of Potent PD-1/PD-L1 Inhibitors

“…12 Given the importance of benzoxazole derivatives in the broad pharmacological classes, 13 the development of synthetic methods for the preparation of the benzoxazole scaffold has been an active area of research. 14 15 Recent trends have focused on the development of greener processes that could reduce the use of toxic reagents or solvents and minimize the production of organic wastes. 16…”

“…12 Given the importance of benzoxazole derivatives in the broad pharmacological classes, 13 the development of synthetic methods for the preparation of the benzoxazole scaffold has been an active area of research. 14,15 Recent trends have focused on the development of greener processes that could reduce the use of toxic reagents or solvents and minimize the production of organic wastes. 16 Figure 1 Selected examples of FDA-approved drugs, and the clinical candidate compound 1, bearing a benzoxazole scaffold 6,10,11 Compound 1 was first described as a programmed death-ligand 1 (PD-L1) inhibitor in Phase 2 of a clinical trial conducted by the Incyte Corporation.…”