Track topics on Twitter Track topics that are important to you
In a one-pot procedure, bromine less brominating reagent 1,1'-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been utilized as an efficient desulfurizing agent for the construction of a library of heterocycles containing N, O, and S starting from aryl/alkyl isothiocyanates. In this approach, aryl/alkyl isothiocyanate reacts with o-phenylenediamine (o-PD), o-aminophenol, and o-aminothiophenol to form their monothiourea which on desulfurization with EDPBT led to the formation of corresponding 2-aminobenzimidazoles, 2-aminobenzoxazoles, and 2-aminobenzothiazoles, respectively. An interesting regioselectivity was observed for unsymmetrical thiourea having a naphthyl moiety on the one side and an ortho amino or an ortho hydroxy phenyl group on the other side giving a completely different product which is mainly dependent on the nature of the nucleophiles (-OH or -NH(2)). Further, the bis-thioureas resulted from the aliphatic 1,2-diamine with 2 equiv of aryl isothiocyanates on treatment with EDPBT gave imidazolidenecarbothioamides, whereas bis-thioureas resulted from aromatic 1,2-diamine yielded benzimidazoles with concurrent expulsion of an isothiocyanate unit. This method is simple and applied to various substrates which are amenable to bromination that reveals the desulfurizing ability of EDPBT predominating over its brominating ability. Finally, the spent reagent EDPDB can be recovered, regenerated, and reused without any loss of activity.
Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781 039, India.
This article was published in the following journal.
Name: Journal of combinatorial chemistry
A versatile and metal-free approach for the synthesis of carbocycles and of heterocycles bearing seven- and eight-membered rings is described. The strategy is based on ring expansion of 1-vinylcycloal...
Reactions of pentaphenylborole with isocyanates, benzophenone, and benzaldehyde produced new seven-membered heterocycles in high yields. For 1-adamantyl isocyanate, a BNC5 heterocycle was obtained fro...
The first total synthesis of (+)-vibsanin A, an 11-membered vibsane diterpenoid, was achieved, unambiguously establishing its relative and absolute stereochemistry. Highlights of the synthesis include...
The preparation, characterization and examination of the CBI-based 5-membered lactone 5 capable of serving as a prodrug or protein (antibody) conjugation reagent are disclosed along with its incorpora...
The development of processes that streamline the synthesis of complex, functionalized carbocycles and heterocycles remains a hotly pursued topic because their scaffolds are present in a range of bioac...
Cholesterol is the precursor of glucocorticoids, mineralocorticoids and sex steroids. Both adrenal and non-adrenal (ovarian + testicular) all steroid hormones are primarily synthesized usi...
The present proposal is designed to examine the effect of carbohydrate and protein co-ingestion on muscle protein synthesis during endurance type exercise activities. We hypothesize that m...
The aim of the present study is to investigate the effect of added protein+leucine or caffeine to 1.2 g/kg/h CHO on the rate of post-exercise muscle glycogen re-synthesis in healthy, recre...
The primary purpose of the study is to evaluate the therapeutic efficacy and safety of cholic acid in subjects with identified inborn errors of bile acid synthesis.
The aim of this study is to measure the variations of serum and urinary hepcidin levels following a single intravenous injection of erythropoietin in healthy volunteers. Hepcidin is a majo...
Six-membered heterocycles containing an oxygen and a nitrogen.
Unsaturated azacyclopropane compounds that are three-membered heterocycles of a nitrogen and two carbon atoms.
Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.
Compounds based on a seven-membered ring fused to a five-membered ring. Heat can rearrange them to NAPHTHALENES which have two fused six-membered rings. They are similar to guaiazulenes which are SESQUITERPENES with a six-membered ring fused to a five-membered ring.
An organic compound used often as a reagent in organic synthesis, as a flavoring agent, and in tanning. It has been demonstrated as an intermediate in the metabolism of acetone and its derivatives in isolated cell preparations, in various culture media, and in vivo in certain animals.