- Synthesis of N-vinylpyrazoles
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A method is proposed for the alkylation of pyrazoles with dichloroethane in water in the presence of the phase-transfer catalyst benzyltriethylammonium chloride (TEBAC). It was shown that dehydrochlorination of the corresponding N-(β-chloroethyl)pyrazoles in water under conditions of phase-transfer catalysis proceeds smoothly with the formation of N-vinylpyrazoles in 80-90% yield. 2005 Springer Science+Business Media, Inc.
- Attarian,Matsoyan,Martirosyan
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p. 452 - 455
(2007/10/03)
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- Pyrazolopyrimidinones which inhibit type 5 cyclic guanosine 3',5'-monophosphate phosphodiesterase (cGMP PDE5) for the treatment of sexual dysfunction
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Compounds of formulae (IA) and (IB) or pharmaceutically or veterinarily acceptable salts thereof, or pharmaceutically or veterinarily acceptable solvates of either entity, wherein R1 is C1 to C3 alkyl substituted with C3 to C6 cycloalkyl, CONR5R6 or a N-linked heterocyclic group; (CH2)nHet or (CH2)nAr; R2 is C1 to C6 alkyl; R3 is C1 to C6 alkyl optionally substituted with C1 to C4 alkoxy; R4 is SO2NR7R8; R5 and R6 are each independently selected from H and C1 to C4 alkyl optionally substituted with C1 to C4 alkoxy, or, together with the nitrogen atom to which they are attached, form a 5- or 6-membered heterocyclic group; R7 and R8, together with the nitrogen atom to which they are attached, form a 4-R10-piperazinyl group; R10 is H or C1 to C4 alkyl optionally substituted with OH, C1 to C4 alkoxy or CONH2; H is an optionally substituted C-linked 5- or 6-membered heterocyclic group; Ar is optionally substituted phenyl; and n is 0 or 1; are potent and selective cGMP PDE5 inhibitors useful in the treatment of, inter alia, male erectile dysfunction and female sexual dysfunction.
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Page column 71
(2010/02/06)
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- Synthesis of vinyl monomers with active azaaromatic groups. Phase-transfer catalytic approach
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An efficient method based on the alkylation-elimination reactions under solid-liquid phase transfer-catalysis conditions (S/L PTC) is reported for the preparation of N-vinyl derivatives of azaheterocyclic compounds.
- Bogdal, Dariusz,Jaskot, Krzysztof
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p. 3341 - 3352
(2007/10/03)
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- Synthesis and Physicochemical Studies on 1,2-Bisazolylethanes
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Twenty symmetrical and asymmetrical 1,2-bisazolylethanes have been obtained from azoles and 1,2-dibromoethane or 1-chloro-2-(pyrazol-1-yl)ethane by phase transfer catalysis (PTC).The 1H and 13C nmr properties are reported and the chemical shifts of the ethylene carbon atoms discussed using an additive model.
- Torres, J.,Lavandera, J. L.,Cabildo, P.,Claramunt, R. M.,Elguero, J.
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p. 771 - 782
(2007/10/02)
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- ALKYLATION OF AZOLES USING beta -FUNCTIONAL ALKYL HALIDES UNDER CONDITIONS OF PHASE TRANSFER CATALYSIS.
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The objective of this study was to develop a convenient synthetic method for direct N-alkylation of pyrazole (I), 3(5)-methylpyrazole (II), 3,5-dimethylpyrazole (III), 1,2,4-triazole (IV), and tetrazole (V) using beta -functional alkyl halides under conditions of two-phase catalysis and with high product yields. This investigation was stimulated by the fact that the desired reaction products are intermediates in the synthesis of an important class of compounds, vinylazole, as well as of various pharmaceutical agents. It is found that depending on the acidity of the azole, alkylation with dichloroethane can be accompanied by beta -elimination. The effect of solvent on the course of alkylation reactions using dichloroethane has also been studied, and revealed that the reactions occur via the intermediacy of ion pairs rather than free anions.
- Asratyan,Attaryan,Pogosyan,Eliazyan,Darbinyan,Matsoyan
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p. 1202 - 1206
(2007/10/02)
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