- Design, synthesis, and structure-activity relationships of pyrazolo[3,4-d]pyrimidines: A novel class of potent enterovirus inhibitors
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A series of pyrazolo[3,4-d]pyrimidines were synthesized and their antiviral activity was evaluated in a plaque reduction assay. It is very interesting that this class of compounds provide remarkable evidence that they are very specific for human enteroviruses, in particular, coxsackieviruses. Some derivatives proved to be highly effective in inhibiting enterovirus replication at nanomolar concentrations. SAR studies revealed that the phenyl group at the N-1 position and the hydrophobic diarylmethyl group at the piperazine largely influenced the in vitro antienteroviral activity of this new class of potent antiviral agents. It was found that the pyrazolo[3,4-d]pyrimidines with a thiophene substituent, such as compounds 20-24, in general exhibited high activity against coxsackievirus B3 (IC50=0.063-0.089μM) and moderate activity against enterovirus 71 (IC50=0.32-0.65μM) with no apparent cytotoxic effect toward RD (rhabdomyosarcoma) cell lines (CC5025μ M).
- Chern, Jyh-Haur,Shia, Kak-Shan,Hsu, Tsu-An,Tai, Chia-Liang,Lee, Chung-Chi,Lee, Yen-Chun,Chang, Chih-Shiang,Tseng, Sung-Nien,Shih, Shin-Ru
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p. 2519 - 2525
(2007/10/03)
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- 3'-Chloro-3α-(diphenylmethoxy)tropane but not 4'-chloro-3α- (diphenylmethoxy)tropane produces a cocaine-like behavioral profile
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A series of 2'- and 3'-substituted and 3',3''-disubstituted 3α- (diphenylmethoxy)tropane analogs were designed and synthesized as novel probes for the dopamine transporter. All the analogs were evaluated for displacement of [3H]WIN 35,428 binding at the dopamine transporter and for inhibition of [3H]dopamine uptake in rat caudate putamen. Compounds were observed to monophasically displace [3H]WIN 35,428 binding to the dopamine transporter with affinities of 21.6-1836 nM (K(i)). Generally, meta- substituted compounds were more potent than benztropine and equipotent to or slightly less potent than their previously reported parasubstituted homologs in inhibiting [3H]WIN 35,428 binding. However, these same metasubstituted analogs were typically less potent than the 4'-substituted analogs in inhibiting [3H]dopamine uptake. Ortho-substituted analogs were generally less potent in both binding and inhibition of uptake at the dopamine transporter than either benztropine or other aryl-substituted homologs. The analogs were also tested for binding at norepinephrine and serotonin transporters as well as muscarinic m1 receptors. None of the compounds in the present study bound with high affinity to either the norepinephrine or serotonin transporters, but all bound to muscarinic m1 receptors with high affinity (K(i) = 0.41-2.52 nM). Interestingly, 3'-chloro-3α- (diphenylmethoxy)tropane (5c) produced effects like cocaine in animals trained to discriminate 10 mg/kg cocaine from saline, unlike its 4'-Cl homolog and all of the previously evaluated benztropine analogs. Further evaluation of compound 5c and the other benztropine analogs will undoubtedly prove useful in the elucidation of the role of the dopamine transporter in the reinforcing effects of cocaine and the ultimate identification of a cocaine-abuse treatment.
- Kline, Richard H.,Izenwasser, Sari,Katz, Jonathan L.,Joseph, David B.,Bowen, Wayne D.,Newman, Amy Hauck
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p. 851 - 857
(2007/10/03)
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- Stabilities of Carbonium Ions. IV. Steric Effects in the Solvolysis of Substituted Diphenylmethyl Chlorides
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The replacement of ortho-hydrogen atoms by methyl groups in diphenylmethyl chloride has three distinguishable results upon the rate of solvolysis.Firstly, the alkyl group activates by its electronic effect; secondly, steric interactions diminish all obsse
- Bolton, Roger,Burley, Rita E.,Williams, Nigel J.
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p. 625 - 634
(2007/10/02)
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- Reactions of 1-tert-Butyl-3-phenylaziridinone and α-Bromo-N-tert-butylphenylacetamide with Benzyl-Grignard Reagents
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1-tert-Butyl-3-phenylaziridinone (1) reacts with benzyl halide Grignard reagents (Br and Cl) to give N-tert-butyl-2,3-diphenylpropanamide (4), N-tert-butyl-2-phenylacetamide (3), N-tert-butyl-2-o-tolyl-2-phenylacetamide (5), 1-(tert-butylamino)-1,3-diphenylpropan-2-one (7), N-benzyl-N-tert-butyl-2-phenylacetamide (6), and N-tert-butyl-2-halo-2-phenylacetamide (2, X = Br, Cl).The choice of solvent appears to determine the relative amounts of products 4 and 5.The bromo amide 2 reacts with the Grignard reagent to give 3, 4, 5, 6, and 7 and may be involved to some extentin the reaction of 1 with benzyl-Grignard reagents.The formation of 5 represents anew type of "abnormal" product from a reaction of the benzyl-Grignard reagent; however, this product appears to fit well into the mechanistic pattern established for prior examples.
- Baumgarten, Henry E.,Chiang, Nein-Chu Robert,Elia, Victor J.,Beum, Paul V.
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p. 5507 - 5512
(2007/10/02)
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