Coumarins are a class of compounds with benzopyrone ring system. In the present work 7-hydroxy-4-methyl coumarin was prepared by the reaction of resorcinol and ethylacetoacetate mixture in the presence of concentrated sulphuric acid. 7-hydroxy-4-methyl coumarin was acetylated with acetic anhydride in the presence of acetic acid. The product formed was treated with bromine in glacial acetic acid...

Lithium-bromine exchange in 2-bromophenyl perfluoroaryl ethers or sulfides affords fused fluorinated benzofurans or benzothiophenes respectively by S(N)Ar substitution of the adjacent fluorine in the perfluoroaryl substituent. The structures of the new compounds were confirmed by NMR spectroscopy and single crystal X-ray diffraction analysis. In the case of 2-bromophenyl tetrafluoropyrid-4-yl e...

1,2,3-triazoles are important scaffolds in several fields, and there is still a demand to construct these compounds, most notably the disubstituted 4, 5 compounds. The latter obtained different ways, but 4- 5-halo triazoles generally key intermediates their synthesis. These halogenated compounds an extraordinary platform leading great chemical diversity around 4 positions. However, own pathways...

A new chemical scheme is developed for the multiphase photochemical box model SEAMAC (sizeSEgregated Aerosol model for Marine Air Chemistry) to investigate photochemical interactions between volatile organic compounds (VOCs) and reactive halogen species in the marine boundary layer (MBL). Based primarily on critically evaluated kinetic and photochemical rate parameters as well as a protocol for...

Of the organic sulfur compounds of biological interest, taurine is unique as the only sulfonic acid derivative known to have its origin in the activity of living cells. Its origin from the cystine of the protein molecule is generally accepted, but proof of the reaction by which it is derived is lacking. Friedmann (1) oxidized cystine to cysteinic acid by bromine water, and was successful in obt...

The objective of this study was to investigate the uptake of deltamethrin, an insecticide, by Daphnia magna neonates by SIMS and to compare these findings with results based on established toxicity tests. Young daphnids (aged <24 h) were exposed to 0, 50 and 200 microg L(-1) (ppb) deltamethrin. Mobile, immobile and dead animals were enumerated after 24 and 48 h following OECD 202 [OECD 202, 200...

We have developed a merged ozone data set (MOD) for the period October 1978 through June 2006 combining total ozone measurements (Version 8 retrieval) from the TOMS (Nimbus 7, Earth Probe) and SBUV/SBUV2 (Nimbus 7, NOAA 9/11/16) series of satellite instruments. We use the MOD data set to search for evidence of ozone recovery in response to the observed leveling off of chlorine and bromine compo...

Decabromodiphenyl oxide (DBDPO) and octabromobiphenyl (OBBP) perform well as fire-retardant additives for thermoplastics. Both compounds have low acute oral toxicity and low skin absorption toxicity. They are neither primary skin irritants or skin sensitizers and are only mildly irritating to the eyes. A 30-day dietary feeding study in rats established 8 mg DBDPO/kg-day as an unequivocal no-eff...

BACKGROUND Urokinase-type plasminogen activator (uPA) plays a major role in extracellular proteolytic events associated with tumor cell growth, migration and angiogenesis. Consequently, uPA is an attractive target for the development of small molecule active site inhibitors. Most of the recent drug development programs aimed at nonpeptidic inhibitors targeted at uPA have focused on arginino mim...

Custard, Kyle David. PhD., Purdue University, May 2015. Studies of Arctic Halogen Chemistry from the Snowpack to the Gas Phase. Major Professor: Paul B. Shepson. The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with ...