Suresh Reddy Cirandur

Green synthesis of α-aminophosphonate derivatives on a solid supported TiO2 -SiO2 catalyst and their anticancer activity.

Syntheses of a new series of biologically potent α‐aminophosphonates were accomplished by one‐pot Kabachnik–Fields reaction using TiO2–SiO2 as solid supported catalyst under microwave irradiation conditions. The chemical structures of all the newly synthesized compounds were confirmed by analytical and spectral (IR, 1H, 13C, 31P NMR, and mass) data. Their anticancer nature was evaluated by screening the in vitro activity on two human cancer cell lines, HeLa and SK‐BR‐3. Compounds 4i and 4o showed the best activity on these cancer cells even though the majority of the compounds, and particularly 4l and 4p, have good cytotoxic activity against them.

Efficient synthesis of polyfunctionalized thiophene-2,3-diones and thiophen-3(2H)-ones using β-oxodithioesters

Efficient methods for the preparation of polyfunctionalized thiophene-2,3-diones and thiophen-3(2H)-ones using β-oxodithioesters were described. In this study, β-oxodithioesters were found to react directly with oxalyl chloride producing 4-aroyl-5-(methylthio)thiophene-2,3-diones in 96–98% yields. However, β-oxodithioesters were found to react efficiently with chloroacetic anhydride in the presence of a base catalyst such as DMAP, which gave 4-aroyl-5-(methylthio)thiophen-3(2H)-ones in 61–77% yields.

Synthesis of N-(3-picolyl)-based 1,3,2λ5-benzoxazaphosphinamides as potential 11β-HSD1 enzyme inhibitors

Inhibition of 11β-HSD1 enzymatic action is perceived as a potential target for the treatment of metabolic syndromes like cardiovascular diseases, obesity, and diabetes. In an attempt to formulate potential organophosphorus compounds against 11β-HSD1 enzyme inhibition, we report novel 6-bromo-3-(6-methyl-2-pyridyl)-2-alkyl/arylamino-3,4-dihydro-2H-1,3,2λ5-benzoxazaphosphinin-2-ones 22a–22n as good in vitro inhibitors of HEK 293 cell lines. The in vivo acute and sub-acute investigations sustain them as good antidiabetic compounds. The computational docking studies performed on them also supported the binding mode of compounds 22a and 22h with 11β-HSD1 protein. The blood glucose level lowering effect of the target compounds 22a–22n screened on the streptozotocin-induced diabetic rats revealed that the target compounds are potential by antidiabetic when compared to the potency of standard glibenclamide drug. In addition, the calculated QSAR parameters, predicted ADMET properties, evaluated bioactivity properties and toxicity risk studies authorize drug like properties to the synthesized compounds.Graphical Abstract

Synthesis and antioxidant activity of some new N -alkylated pyrazole-containing benzimidazoles

A series of new N-substituted pyrazole-containing benzimidazoles was synthesized starting from 1,2-diaminobenzene and pyrazole-4-carbaldehyde in good yield. Antioxidant activity of all title compounds was assessed using 2,2-diphenyl-1-picrylhydrazyl and hydrogen peroxide assays. Some of the synthesized compounds having benzyl substituent at the imidazole nitrogen exhibited good activity in both assays.

A simple and convenient protocol for the synthesis of seven- and eight-membered phosphorus heterocycles

ABSTRACT A simple procedure for the synthesis of eight-membered 6-(2-chloroethyl)/bis(2-chloroethyl)-amino-12-oxo-dibenzo[d,g][1,3,2]dioxaphosphocin 6-oxides (3a–b) and seven-membered 6-(2-chloroethyl)/bis-(2-chloroethyl)aminodibenzo[d,f][1,3,2]dioxaphosphepin 6-oxides (5a–b) from cyclocondensation of equimolar ratios of 2,2′-dihydroxybenzophenone (1) and 2,2′-dihydroxybiphenol (4), respectively with 2-chloroethylphosphonicdichloride (2a) and bis(2-chloroethyl)phosphoramidic dichloride (2b) in dry toluene in the presence of triethylamine at 45–50 °C is described. All synthesized compounds possessed significant growth inhibition for their antibacteria against ‘Bacillus subtilis’ and ‘Klebsiella pneumonia’ and antifungi activity on “Curvularia lunata” and “Aspergillus niger.” GRAPHICAL ABSTRACT

Polyethylene glycol (PEG-400): An efficient medium for the synthesis of 1,2-disubstituted benzimidazoles

Abstract Polyethylene glycol (PEG-400) was found to be an inexpensive, non-toxic, and effective medium for the one-pot synthesis of 1,2-disubstituted benzimidazoles in excellent yields. Eco-friendliness, low cost, high yields, and recyclability of the PEG-400 are the important features of this protocol.