Simple and practical halogenation of arenes, alkenes and alkynes with hydrohalic acid/H2O2 (or TBHP)

Synthesis of dibromo ketones by the reaction of the environmentally benign H2O2-HBr system with oximes

It was found that oximes undergo deoximation in the presence of the H2O2aq-HBraq system to form ketones and bromo ketones. This reaction provided the basis for the synthesis of dibromo ketones in yields varying from 40% to 94%. This method is environmentally friendly, sustainable, and easy to perform. The results of this investigation extend the potential of the use of oximes for the protection of carbonyl group, thus offering the ability to perform not only conventional deoximation but also the subsequent bromination of ketones. The reaction is easily scaled up and dibromo ketones can be prepared in gram amounts.

An Environment Friendly Preparation of 3-Bromocamphor and Camphorquinone

The bromination of camphor has been carried out on a multi-gram scale by a mixture of KBr and KBrO3 in the presence of acid or with HBr/NaBr - H+ and H2O2/oxone® as the oxidant. The 3-bromocamphor is then efficiently converted to camphorquinone by an improved oxidation protocol using DMSO and sodium carbonate of tetrabutyl ammonium iodide.

Studies on the anti-hepatitis C virus activity of newly synthesized tropolone derivatives: identification of NS3 helicase inhibitors that specifically inhibit subgenomic HCV replication

We synthesized new tropolone derivatives substituted with cyclic amines: piperidine, piperazine or pyrrolidine. The most active anti-helicase compound (IC50=3.4 microM), 3,5,7-tri[(4'-methylpiperazin-1'-yl)methyl]tropolone (2), inhibited RNA replication by 50% at 46.9 microM (EC50) and exhibited the lowest cytotoxicity (CC50)>1 mM resulting in a selectivity index (SI=CC50/EC50)>21. The most efficient replication inhibitor, 3,5,7-tri[(4'-methylpiperidin-1'-yl)methyl]tropolone (6), inhibited RNA replication with an EC50 of 32.0 microM and a SI value of 17.4, whereas 3,5,7-tri[(3'-methylpiperidin-1'-yl)methyl]tropolone (7) exhibited a slightly lower activity with an EC50 of 35.6 microM and a SI of 9.8.

Bromination of Alkenes and Alkynes with (Bromodimethyl)Sulfonium Bromide

Alkenes and alkynes were brominated efficiently in high yields with (bromodimethyl)sulfonium bromide in acetonitrile at room temperature. Alkenes produced the corresponding trans-dibromo compounds while alkynes (except phenylacetylene) afforded both the trans-dibromo products (major) and the tetrabromo derivatives (minor). However, phenylacetylene furnished solely the tetrabromo compound.

Synthesis of some bioactive 2-bromo-5-methoxy-N'-[4-(aryl)-1,3-thiazol-2-yl]benzohydrazide derivatives

Eight novel 2-bromo-5-methoxy-N'-[4-(aryl)-1,3-thiazol-2-yl]benzohydrazide derivatives were prepared and characterized by analytical and spectral analyses. All the compounds were screened for their analgesic, antifungal and antibacterial activities and three of the compounds were screened for antiproliferative activity. Two of the newly synthesized compounds exhibited promising analgesic activity and one compound exhibited in vitro antiproliferative activity.

Chlorination of aromatic compounds in micellar media: regioselectivity

Chlorination of phenol and ortho-chlorophenol was studied in micellar media in order to observe the effect on regioselectivity. Hydrogen peroxide/hydrochloric acid-aqueous system, which is environmentally a safer route was employed for chlorination. Selectivity ratio was found to be dependent on the nature and concentration of the surfactant. Ortho/para selectivity ratio up to 12 was realized for the chlorination of phenol. 2,6-/2,4-dichlorophenol ratio up to 1.01 was realized for the chlorination of ortho-chlorophenol.

Evaluation of 8-Arylsulfanyl, 8-Arylsulfoxyl, and 8-Arylsulfonyl Adenine Derivatives as Inhibitors of the Heat Shock Protein 90

Hsp90 is a chaperone protein with important roles in maintaining transformation and in elevating the survival and growth potential of cancer cells. Currently there is an increasing interest in developing inhibitors of this protein as anticancer therapeutics. One of such inhibitors, the purine-scaffold class, has been reported to be potent and selective against Hsp90 both in vitro and in vivo models of cancer. Here, a series of 8-arylsulfanyl, -sulfoxyl, and -sulfonyl adenine members of the purine class was synthesized and evaluated as inhibitors of the chaperone. The structure-activity relationship and selectivity for tumor Hsp90 of compounds within the series is presented. Our results suggest that 8-arylsulfanyl adenine derivatives are good inhibitors of chaperone activity, whereas oxidation of the sulfides to sulfoxides or sulfones leads to compounds of decreased activity. The study identifies derivative 11v as the most potent Hsp90 inhibitor of the purine-scaffold series published to date (EC(50) = 30 nM), and also as the compound of this class with highest selectivity for tumor vs normal cell Hsp90 (700 to 3000-fold). Most rewardingly, this work has allowed for the identification of Hsp90 inhibitors with selective affinities for Hsp90-client protein complexes, derivatives that may represent useful pharmacological tools in dissecting Hsp90-regulated processes.

Development of a purine-scaffold novel class of Hsp90 binders that inhibit the proliferation of cancer cells and induce the degradation of Her2 tyrosine kinase

The first published synthesis and characterization of a purine-scaffold library of hsp90 inhibitors is presented. The purine-scaffold represents a platform for the creation of easily synthesizable and derivatizable soluble molecules that are amenable for oral administration. The most active compound of the series (71) exhibits binding to hsp90 comparable to the natural product derivative 17AAG that is now in Phase I clinical trial as a cancer therapeutic. Induces the degradation of Her2 tyrosine kinase and arrests the MCF-7 breast cancer cell line at low micromolar concentrations (IC50=2 microM).