K. V. V. Krishna Mohan

Liquid phase bromination of phenols using potassium bromide and hydrogen peroxide over zeolites

An efficient, simple, mild and regioselective method for oxybromination of phenols catalyzed by CrZSM-5(30) is reported. The electrophilic substitution of bromine generated in situ from KBr as a bromine source and hydrogen peroxide as an oxidant.

Zeolite catalyzed acylation of alcohols and amines with acetic acid under microwave irradiation

Zeolite Hβ is found to be an efficient catalyst for the acylation of alcohols and amines with acetic acid under microwave irradiation. The process is environmentally safe and heterogeneous with excellent yields.

Novel Bromination Method for Anilines and Anisoles Using NH4Br/H2O2 in CH3COOH

Abstract A simple, efficient, regioselective, environmentally safe, and economical method for the oxybromination of anilines and anisoles without catalyst is reported. The electrophilic substitution of bromine generated in situ from ammonium bromide as a bromine source and hydrogen peroxide as an oxidant for the first time. #IICT Communication No. 01/X/07.

Liquid phase oxidation reactions over MoMCM-41 and WMCM-41 molecular sieves

Abstract The oxidation of 2-methyl-naphthalene (2MN) to 2-methyl-1,4-naphthoquinone (2MNQ), vitamin K 3 (menadione) was carried out over MoMCM-41 mesoporous molecular sieve catalyst. The typical reaction run was carried out using acetic acid as a solvent, hydrogen peroxide (H 2 O 2 ) as an oxidant, in the temperature range of 60-120 o C for 2-12 h. The liquid product selectivities to 2-methyl-1,4-naphthoquinone were 85, 80, 81 and 79 percent at 12, 69, 98 and ∼99 percent conversions of 2MN for the molar ratio of 2MN:H 2 O 2 equal to 1:2, 1:4, 1:6 and 1:7 respectively. The effect of the various parameters including reaction temperature, molar ratio of 2MN:H 2 O 2 , Si/Mo ratio, various catalysts, various solvents, the various molybdenum precursors and amount of catalyst were studied. The selectivity to benzaldehyde was ∼99 percent at ∼50 percent conversion of styrene over WMCM-41 mesoporous molecular sieve catalyst.