The aerial parts of Tephrosia carrollii afforded two chromene chalcones. Their structures and stereochemistry were established by spectroscopic methods. The structure of oaxacacin was revised and confirmed by X-ray diffraction. In this paper, we describe the isolation of the chalcone known as "oaxacacin" and the new chalcone named epoxyobovatachalcone. The compound der. oaxacacin was found to b...

Poliovirus type 2 Sabin mutants were selected for drug resistance and dependence by plating on HeLa cell monolayers in the presence of 3(2H)-isoflavene, a compound related to dichloroflavan, which prevents the shut-off of host translation and poliovirus RNA and protein synthesis. The drug-resistant mutants grew equally well in the presence and in the absence of the drug, while the drug-dependen...

Nine isotopomers of tryptamine and its halogen derivatives, labeled with deuterium, tritium in side chain, i.e., [(1R)-2H]-, [(1R)-3H]-, 5-F-[(1R)-2H]-, 5-F-[(1R)-3H]-, 5-Br-[(1R)-2H]-, double labeled [(1R)-2H/3H]-, 5-F-[(1R)-2H/3H]-, and ring labeled [4-2H]-, and [5-2H]-tryptamine, were obtained by enzymatic decarboxylation of l-Trp and its appropriate derivatives in deuteriated or tritiated m...

Copper(I) complexes of a new participative triphosphane ligand (2H) have been prepared and structurally characterized: in particular, [Cu(2H)I] [Cu(2)]2. Hydrogenation the latter species afforded trimetallic hydride [Cu3(2)2(μ-H)] or, presence BEt3, [Cu(2H)(HBEt3)]. Their formation evidences transient [Cu(2H)H] formed by hydrogenolysis Cu–N bond [Cu(2H)(HBEt3)] behaves like complex inserts CO2 ...

Efficient kinetic resolution of racemic 3-nitro-2H-chromenes by bifunctional thiourea afforded optically active (R)-3-nitro-2H-chromene derivatives with moderate to good enantioselectivities, which simultaneously gave the multifunctional 3,4-diphenyl-3a-nitrobenzopyrano-[3,4-c]-pyrrolidine-1,1-dicarboxylate derivatives with four vicinal chiral carbon centers.

We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (2) was prepared from (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid ethyl ester (1) and 100% hydrazine hydrate. Compound 2, is the key intermediate for the synthesis of several series of new compounds such as Schiff's bases 3a-l, formic acid N'-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)acetyl] hydrazide (4), acetic acid N'-[2-(7-hydroxy-2-oxo-2...

Nucleophilic substitution reactions of 2-halo-2H-azirines 1a, 1b, 1d, and 1e with potassium phthalimide and aniline allowed the preparation of new substituted 2H-azirines 2-5. The reactions of 2-bromo-2H-azirine 1a with methylamine led to the synthesis of alpha-diimines 7 and 8. 2-Halo-2H-azirines were also established as building blocks for the synthesis of a range of heterocyclic compounds, n...

A procedure has been developed for synthesis of 2-alkenyl-2H-indazoles starting from 2-(2-carbonylmethyl)-2H-indazoles, which are prepared by gallium/aluminium- and aluminium-mediated, direct, regioselective alkylation of indazoles with α-bromocarbonyl compounds. The structure of 3-(2H-indazol-2-yl)-2H-chromen-2-one was proven by X-ray crystallography. The styrene- and coumarin-2H-indazoles pro...