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1.
Several 6-phenyl-3(2H)-pyridazinones bearing different alkenyl groups at position 5 have been prepared in the search for novel antiplatelet agents. The target compounds were synthesised by a palladium-catalysed Heck cross-coupling reaction. Variable amounts of 4-phenyl-6-substituted-2-phthalazinones were isolated as by-products during these experiments. The crucial issues for successful Heck coupling in these systems concern the protection of position 2 of the heterocyclic ring and the use of tris(o-tolyl)phosphine as a ligand. 相似文献
2.
A series of 6-phenyl-3(2H)-pyridazinones bearing different substituents in the 5-position of the pyridazinone ring were prepared using Stille-based approaches in the search for new platelet-aggregation inhibitors. 相似文献
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Several 6-phenyl-3(2H)-pyridazinones bearing different alkynyl groups at position 5 have been prepared by a palladium-catalysed Sonogashira cross-coupling reaction. An interesting base-promoted electronically permitted isomerization has been observed during the coupling of 1-phenyl-2-propyn-1-ol. This rearrangement afforded the E-chalcone 6 in excellent yield. 相似文献
5.
Ulrike Gabriella Wagner Christoph Kratky Thomas Kappe 《Monatshefte für Chemie / Chemical Monthly》1989,120(4):329-342
Summary The synthesis of the title compound7 was achieved starting with mucochloric acidvia the pyridazinones1,2 and6. The electrolytic ionisation constants for7 were found to be 4.81 (±0.03) and –0.3 (±0.3). Crystal structure analyses were performed for7 and its fixed derivatives6 and9.Dedicated to Prof. Dr. Hans Junek on the occasion of his 60th birthday 相似文献
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Preparation of a number of derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP) including the 2-dialkylaminoalkylamino-, 2-hydroxyalkylamino-, 2-ethoxycarbonylamino- and 2-alkylaminocarbonyl-amino- groups substituted on the pyrimidine ring as well as preparation of 1-(alkylaminoalkyl)-4,6-dioxo-8-phenyl-2,3,4,6-tetrahydro-1H-pyrimido[1,2-α]pyrimidines and 3,5-dioxo-7-phenyl-1,2,3,5-tetrahydroimidazo-[1,2-α]pyrimidines with or without the bromo-substitution are reported. 相似文献
8.
Several benzothiazolyl, imidazobenzothiazolyl, benzothienyl, benzothienopyrimidinyl and quinazolinyl 4,5-dihydro-3(2H)-pyridazinones were synthesized and examined for cardiotonic activity in anesthetized dogs after i.v. administration. Among them, 4-methylamino-7-(2,3,4,5-tetrahydro-5-methyl-3-oxo-6- pyridazinyl)quinazoline (36) showed potent and long-lasting inotropic activity (relative potency = 2.11, milrinone = 1). The activity of 36 was more potent than indolidan (2) (relative potency = 1.53) which is one of the most potent inotropic agents to date. 相似文献
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6-Chloro-2-diethylaminoethyl-3(2H)-pyridazinone was synthesized by the reaction of 6-chloro-3(2H)-pyridazinone and 2-diethylamionethyl chloride reaction in methylbenzene.Then the structure was characterized by means of ^1H NMR,IR,UV.By the method of ab initio HF and density functional theory(DFT) BeLYP,the geometric structures of the reagent intermediate,the product and its isomer were optimized and their total energies were calculated,The properties for the frontier molecular orbitals and the rules for energy distribution were analyzed systematically.It was shown that the energy of the nitrogen alkyl compound is lower than that of the oxy alkyl compound and the former is stable than the latter.This result is in accordance with the fact that 6-chloro-2-diethylaminoethyl-3(2H)-pyridazinone is synthesized by the reaction of 6-chloride-2-diethylaminoethyl-3(2H)-pyridazinone and 2-diethylaminoethyl chloride. 相似文献
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Alberto Coelho Eddy Sotelo Hctor Novoa Oswald M. Peeters Norbert Blaton Enrique Ravia 《Tetrahedron》2004,60(52):12177-12189
In the search for novel antiplatelet agents, convenient and efficient methods for the preparation of 2,5-disubstituted pyridazin-3(2H)-ones are reported that utilise palladium-catalysed cross-coupling reactions. A post-coupling base-promoted isomerisation has been observed during Sonogashira alkynylation of 5-iodopyridazin-3(2H)-ones (3) with 1-phenyl-2-propyn-1-ol. Variable amounts of phthalazinones were isolated as by-products during the Heck alkenylation of 3. The usefulness of the hydroxymethyl fragment as a protecting group during the synthesis of 5-substituted pyridazin-3(2H)-ones has been validated. 相似文献
14.
The nucleophilic introduction of chloro- ( 2 ), azido- ( 4 ), (substituted) amino ( 3, 6 ), mercapto ( 10 ) and hydrazino-groups ( 13 ) into 2-aryl-5-hydroxypyridazin-3(2H)-ones [3] is described. The 5-aminopyridazin-3(2H)-one ( 6 ) also reacts with activated malonates 8 [4] to give pyrido[2,3-d]pyridazines 9 . Hydrazino compounds 13 can be treated with aldehydes to yield compounds 14 . Iodine can be introduced into position 4 of 5 -amino -(15 ) and 5-hydroxypyridazin-3(2H)-ones ( 17 ) by electrophilic substitution to afford compounds 18 . 相似文献
15.
5-Alkynylpyridazin-3(2H)-ones or 5-(2-chloroalkenyl)pyridazin-3(2H)-ones were isolated during the cleavage of the methoxymethyl group in a series of 5-alkynyl-2-methoxymethylpyridazin-3(2H)-ones by treatment with hydrochloric acid. The efficient and selective cleavage of the methoxymethyl group in these compounds can be performed under mild conditions by employing aluminium chloride. 相似文献
16.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1990,46(7):1087-1096
The infrared spectra of 3(2H)-pyridazinone and its rare tautomeric form, 3-hydroxypyridazine, isolated in an argon matrix are reported and discussed. Only the first tautomer was observed after deposition of the matrix. The second form was photochemically produced after ultraviolet irradiation of the matrix (phototautomeric process). This form has never been observed experimentally before. Ab initio 3-21G normal coordinate calculations were carried out for these two forms and on that basis, an assignment of the experimental spectra of both compounds was performed. 相似文献
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Contributions to the Chemistry of Phosphorus. 67. About the Cyclotriphosphanes (PC6H5)3, (PC6H5)2(PC2H5), and (PC6H5)2(PCH3) The reaction of (CH3)3Si(C6H5)P? P(C6H5)Si(CH3)3 with RPCl2 (R = C6H5, C2H5, CH3) yields the cyclotriphosphanes (PC6H5)3 1 , (PC6H5)2(PC2H5) 3 , and (PC6H5)2(PCH3) 4 , respectively. Besides, the corresponding homo- and mixed-substituted cyclotetraphosphanes, cyclopentaphosphanes, and cyclohexaphosphanes are formed. The relative concentrations of the cyclotriphosphanes in the reaction mixtures decrease continuously, whereas those of the cyclopentaphosphanes increase. The reasons for these ring-interconversion reactions of the cyclophosphanes (PR)n are discussed. The cyclotriphosphanes 1, 3 , and 4 are characterized by 31P chemical shifts between +130 and +160 ppm that are at considerable high field compared to open-chain triphosphanes and cyclophosphanes of different ring-size. The substituents R are situated on both sides of the P3-ring plane, thus giving rise to two diastereomers of 3 that are observed simultaneously in the statistically expected ratio. The 31P n.m.r. parameters of 1 and 3 are reported and discussed. 相似文献
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Condensation of ethyl benzylidenecyanoacetate with thiocarbamoylacetamide in the presence of an equimolar amount of piperidine
produces piperidinium 5-carbamoyl-3-cyano-2-oxo-4-phenyl-3,4-dihydropyridine-6(1H)-thiolate, which is then used in synthesis
of the corresponding 6-alkylthiosubstituted 3,4-dihydropyridin-2(1H)-ones.
Dedicated to Professor Henk van der Plas on his 70th birthday.
Latvian Institute of Organic Synthesis, Riga LV-1006
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 506–509, April, 1999. 相似文献