Topic
Bicyclic molecule
About: Bicyclic molecule is a research topic. Over the lifetime, 29587 publications have been published within this topic receiving 451252 citations. The topic is also known as: bicyclic molecule.
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TL;DR: A correlation involving chemical reactivity, microbiological activity, and 3-substituent sigma p values was observed, and the correlation has led to the synthesis of new more potent bicyclic pyrazolidinones.
Abstract: The acylating ability of the gamma-lactam ring of a new class of antibacterial agent, the bicyclic pyrazolidinones 1, was compared to that of the beta-lactam ring of clinically useful antibiotics by measuring chemical reactivity with hydroxide ion. The pyrazolidinone chemical reactivity spans the reactivity of classical beta-lactam antibiotics and the most reactive, 1i, is 13 times more reactive than the most reactive beta-lactam examined, ceftazidime. A correlation involving chemical reactivity, microbiological activity, and 3-substituent sigma p values was observed, and the correlation has led to the synthesis of new more potent bicyclic pyrazolidinones.
72 citations
TL;DR: In this article, the phase-transfer catalyst TDA-1 was used to improve the performance of Wittig reactions with cyclopropylidenetriphenylphosphorane.
72 citations
Patent•
02 Mar 2005
TL;DR: In this paper, a set of compounds are provided that act as potent modulators of one or more of the CCR1, CCR2 and CCR3 receptors, which are generally fused-, spiro- or bridged-nitrogen heterocycles having an aryl and heteroaryl component.
Abstract: Compounds are provided that act as potent modulators of one or more of the CCR1, CCR2 and CCR3 receptors. The compounds are generally fused-, spiro- or bridged-nitrogen heterocycles having an aryl and heteroaryl component and are useful in pharmaceutical compositions, methods for the treatment of CCR1-, CCR2- and/or CCR3-mediated diseases, and as controls in assays for the identification of competitive receptor antagonists for the above chemokine receptors.
72 citations
TL;DR: It is observed that optimal mu/kappa-receptor selectivity is obtained when the oxygen atom of the methyl ether or the tetrahydrofuran ring is joined to the equatorial C-4 position.
Abstract: This paper describes the chemical synthesis, mu/kappa opioid receptor selectivity and analgesic activity of 14 novel N-[2-(1-pyrrolidinyl)-4- or -5-substituted-cyclohexyl]arylacetamide derivatives. The prototype kappa-selective agonist, PD117302 (trans-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzo[b]thiophene-4- acetamide, 2) has been regio- and stereoselectively substituted in the C-4 and C-5 positions of the cyclohexyl ring with the methyl ether and spiro tetrahydrofuran groups. It is observed that optimal mu/kappa-receptor selectivity is obtained when the oxygen atom of the methyl ether or the tetrahydrofuran ring is joined to the equatorial C-4 position. Hence, (-)-(5 beta,7 beta,8 alpha)-N-methyl-N-[7-(1-pyrrolidinyl)-1- oxaspiro[4.5]dec-8-yl]benzo[b]furan-4-acetamide monohydrochloride (21) has exceptionally high kappa opioid receptor affinity and selectivity in vitro (kappa Ki = 0.83 nM, mu/kappa ratio = 1520) is the most potent kappa-selective analgesic ever reported. Compound 21 is 25 times more potent than morphine and 17 times more potent than U-62066 (spiradoline, 19) when assayed by the rat paw pressure test by intravenous administration (MPE50 = 0.024, 0.6, and 0.4 mg/kg, respectively).
72 citations
TL;DR: Results are important for the design of near-infrared absorbing azo dyes and suggest an efficient path for the preparation ofNear-inf infrared absorbing azos dyes by effectively enhancing pi-electron delocalization.
Abstract: Symmetric 2,5-bisazopyrroles 2(a-d) were synthesized by a one-step reaction of substituted phenyl diazonium salts [R'(Ph)N2(+)Cl-] [a, R' = 4-N(CH3)2; b, R' = 2-OH; c, R' = 2-CO2H; d, R' = 4-NO2] with pyrrole under basic conditions. Asymmetric 2,5-bisazopyrroles 3(a-d) were synthesized by reacting substituted phenyl diazonium salts [R''(Ph)N2(+)Cl-] (a, R'' = 4-OCH(3); b, R'' = H; c, R'' = 4-Br; d, R'' = 4-NO2) with 2-(4-dimethylaminophenylazo)-1H-pyrrole (1a) under the same conditions. The reactions of 2a with boron trifluoride and iodomethane provided a BF2-azopyrrole complex of 1H-pyrrolo[2,1-c]-1,2,4,5-boratriazole (4) and 2,5-bisazo-1-methylpyrrole 5. X-ray crystallographic and spectral analysis of 1a, 2a, 2b, and 4 showed that 1a has three crystal forms: 1a(I), 1a(II), and 1a(III), the latter two bearing a bicyclic ring system formed via intermolecular hydrogen bonding. Complex 4 was found to be the most planar due to a rigid trans-azo configuration and has the longest N horizontal lineN bond distances (1.322 and 1.300 Angstrom) and wavelength of maximum absorption (754 nm). The N horizontal lineN bond distances increase in the sequence of monoazopyrrole [1a(I): 1.253 Angstrom], bisazopyrrole (2a: 1.283 Angstrom), bisazopyrrole with intramolecular hydrogen bonding (2b: 1.293 and 1.293 Angstrom), and the BF2-azopyrrole complex. Their maximum absorptions shift bathochromically in the sequence of monoazopyrrole (1a: 443 nm), bisazopyrroles [2(a-d), 3(a-d), 5: 486-615 nm], and the BF2-azopyrrole complex. These results are important for the design of near-infrared absorbing azo dyes and suggest an efficient path for the preparation of near-infrared absorbing azo dyes by effectively enhancing pi-electron delocalization.
72 citations