barium salts of dibenzylidene cystines 8a-c were obtained from the reaction of lcystine with benzaldehyde or its derivatives in the presence of barium hydroxide. their reduction with zinc and hydrochloric acid in methanol yielded the narylmethylcysteines ?9a-c?. these can, in turn, be converted by esterification into the methyl esters ?10 a-c. ?reaction of n, n'-carbonyl diimidazole (im co...

nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...

background: 2, 4-dichlorophenoxy acetic acid (2, 4-d) is well known as inexpensive herbicides but it can give rise to undesirable pollution. the objective of this investigation was to describe a photo-chemical system for degradation of 2, 4-d. methods: a designed photolytic cell system was used in this study with a 150w or 400w uv lamp. a set of experiments was carried out at ph 1.5, 2.5, 3.5 a...