Energy efficient, clean and solvent free photochemical benzylic bromination using NBS in concentrated solar radiation (CSR)

© 2015 Elsevier Ltd. An environmentally benign, clean, solvent free approach for the benzylic bromination have been developed using concentrated solar radiation (CSR). CSR methodology was used as an energy source to the reaction media. The protocol was found to be superior to the conventional photochemical and thermal methods in terms of reaction time and total energy requirement. This method was adapted with concentrated solar radiations in solvent free conditions without the use of radical initiators and has proved to provide good yields. Incorporation of renewable energy source, minimisation of raw materials makes the process not only green but energy efficient also

Synthesis and application of metal complex dyes derived from 5-arylazo-4-hydroxy-2-phenylpyridazin-3-one

142-144Six monoazo metal complex dyes (VIII a-c and IX a-c) were derived from 5-arylazo-4-hydroxy-2-phenylpyridazine-3-ones (VI and VII) respectively and their dyeing performance on wool fibres was assessed. The compounds VI and VII were obtained by the diazotisation of 5-amino-4-chloro-2-phenylpyridazin-3-one (IV) and its coupling with gamma acid and schaffer's acid respectively. The key compound IV was prepared by the ammonolysis of 4.5-dichloro-2-phenylpyridazin-3-one (III) which was obtained by the condensation of phenylhydrazin (I) and mucochloric acid (II). The metal complex dyes when applied on wool fibres gave reddish violet to brown shades with excellent pick-up, light fastness and wash fastness

Synthesis of chalcone (3-(4-fluorophenyl)-1-(4-methoxyphenyl) prop-2-en-1-one): advantage of sonochemical method over conventional method

In this work, an attempt was made to synthesize chalcone (3-(4-fluorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one) by condensation of 4-fluorobenzaldehyde with 1-(4-methoxyphenyl)ethanone under basic conditions by using both conventional (NUS) and sonochemical (US) methods. A simple condensation reaction of 4-fluorobenzaldehyde and 1-(4-methoxyphenyl)ethanone using potassium hydroxide as a base was carried out for the study. The synthesized chalcone derivative was characterized for FTIR, NMR, elemental analyses and studied for XRD, PSM, TGA and SEM properties to evaluate its performance obtained under ultrasonic energy. It was observed that complete conversion to chalcone occurred in 10 min by sonochemical method and in 4 h by conventional method. Also it was found that crystallinity of the US synthesized chalcone was found to be increased by 63% than that of NUS synthesized chalcone. Finally, it has been observed that chalcone synthesis using sonochemical method is an energy efficient technique over conventional method (almost 90% of energy saving)