Non-hazardous synthesis of isocephosphorin intermediates via α-vinylamino-β-lactams

The reaction of a Schiff Base derived from veratrylamine and cinnamaldehyde with (α-methyl-β-alkoxycarbonyl)-vinylamino acetic acid (from glycine and an acetoacetate ester) in presence of a chloroformate ester and triethylamine constitutes a safe synthesis of α-vinylamino β-lactams that can be converted by literature methods to known intermediates for the synthesis of isocephalosporins and analogs.     

Modeling of the electrostatic corona discharge reactor

A model is presented for the electrostatic corona discharge reactor (ECDR) in a pin-plate configuration. The main objective is to describe the fundamental chemistry and physics governing the discharge behavior and to predict the ECDR performance under various operating conditions. The electric field strength is estimated assuming a space-charge-free field. A two-term spherical harmonic expansion is used to solve the Boltzmann equation for the electron energy distribution function (EEDF) and calculate the electron-molecule reaction rates using collision cross-section data. Species continuity equations are solved for the dry and wet air systems to predict ozone and NO_x at various feed flow rates (1630, 4890, 14, 670 cm/s) and an applied voltage of 10 kV. Among the various results reported, it is noted that the calculations indicate the Maxwell EEDF cannot be used because it overpredicts the electron-molecule rate coefficients by several orders of magnitude     

Synthesis,biological evaluation and molecular docking studies of novel 2-(2-cyanophenyl)-N-phenylacetamide derivatives

A series of novel 2-(2-cyanophenyl)-N-phenylacetamide derivatives 3(a-u) were designed and synthesized via selective amidation of methyl-2-(2-cyanophenyl)acetates over amidine formation by using AlMe₃ as catalyst in good yields. All the newly synthesized derivatives were well characterized by ¹H NMR, ¹³C NMR, FTIR and HRMS spectral techniques. All the synthesized title compounds were evaluated for their in vitro anticancer activity against three cancer cell lines. Among all compounds, 3i (IC₅₀?=?1.20 μM, IC₅₀?=?1.10 μM), 3j (IC₅₀?=?0.11 μM, IC₅₀?=?0.18 μM), 3o (IC₅₀?=?0.98 μM, IC₅₀?=?2.76 μM) showed excellent inhibitory activity than the standard Etoposide (IC₅₀?=?2.11 μM, IC₅₀?=?3.08 μM) against MCF-7 and A-549 cell lines, respectively. Docking analysis of all the compounds with the human topoisomerase II revealed that the compound 3j fitted well in the active site pocket, showing the best docking score of 158.072 kcal/mol.

     

A convenient synthesis of α-amino-β-lactams

A safe and convenient method is described for the synthesis of α-amido-β-lactams starting with glycine and an azomethine. The amino group of glycine is protected by reaction with a β-dicarbonyl compound following the method of Dane etal. and the carboxyl group is activated through the formation of a mixed anhydride or an active ester. Condensation between these glycine derivatives and acyclic or cyclic imino compounds (including thioimidates) in presence of triethylamine leads to stereospecific synthesis of 3-(β-carbonyl-vinylamino)-2-azetidinones in 40–60% yield. The vinylamino side chain can be hydrolyzed under mild acid conditions to form 3-amino-2-azetidinones which can be acylated to α-amido-β-lactams. Alternatively, the vinylamino side chain can be converted to an amido side chain by ozonolysis. The molecular parameters of a 3-(β-carbonyl-vinylamino)-2-azetidinone were determined by X-ray crystallography. Usefulness of this α-amido-β-lactam synthesis is illustrated by the preparation of isotopelabeled β-lactams and intermediates for some β-lactam antibiotics.     

An alternative total synthesis of Patulolide A

A new total synthesis of [R]‐Patulolide A from readily available (R)‐propylene epoxide obtained using the asymmetric synthetic approach is reported. The key reactions involved are ozonolysis and Yamaguchi macrolactonization, resulting in the ring system.