G. Chandra Sekhar Reddy

Green Synthesis of Aminobisphosphonates Under Microwave Irradiation

Abstract A simple, efficient, and environmentally benign green chemical method has been developed for the synthesis of aminobisphosphonates by reacting aliphatic/aromatic 2°-amines, dimethylphosphite, and triethylorthoformate by microwave irradiation under solvent-free conditions, in the presence of an alumina solid support. The advantages of this method are less reaction time, simple work-up, and excellent yields. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT

Synthesis and Bioassay of Alkyl-2-[(5,6-dimethyl-2-sulfido-1,3,4,7,2-dioxadiazaphosphepin-2-yl)amino] Alkyl/Aryl Esters

Synthesis of alkyl-2-[(5,6-dimethyl-2-sulfido-1,3,4,7,2-dioxadi- azaphosphepin-2-yl)amino]alkyl/aryl esters (3a–j) was accomplished via a two-step process. It involves the prior preparation of monochloride intermediate (2) and its subsequent reaction with the amino acid esters in dry tetrahydrofuran in the presence of triethylamine at reflux temperature. These compounds were characterized by infrared (IR), 1H-, 13C-, and 31P-nuclear magnetic resonance (NMR), and mass and elemental analysis and were found to exhibit potent antimicrobial activity.

Solvent-free synthesis of novel 2,10-dichoro-12-trichloromethyl-6-substituted xanthato-12H-dibenzo[d,g] [1,3,2] dioxaphosphocin-6-sulfides

Abstract 2,10-Dichloro-12-trichloromethyl-6-substituted xanthato-12H-dibenzo[d,g] [1,3,2] dioxaphosphocin-6-sulfides (2a–l) with the eight-membered phosphorus and oxygen heterocyclic ring were synthesized by reacting equimolar quantities of alcohols, carbon disulfide, and 2,6,10-trichloromethyl-12H-dibenzo[d,g][1,3,2] dioxaphosphocin-6-sulfide 1 in the presence of dimethylaminopyridine (DMAP). The structures of the products were confirmed by IR, 1H, 13C, 31P-NMR, and mass spectral analyses.

Preparation of Tetraoxadiphosphadiborocane-2,6-diones

Abstract Cyclization of aryl/alkyl phosphonic dichlorides (2a–f) with phenylboronic acid/K2CO3/I2 in dry toluene at 60–70 °C afforded 2,6-diaryl/alkyl-4,8-diphenyl-1,3,5,7,2λ 5,6λ 5,4,8-tetraoxadiphosphadiborocane-2,6-diones (3a–f). GRAPHICAL ABSTRACT