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A number of 2-substituted-2-thiazolines have been found to react readily with two moles of isocyanic acid in ethereal solution to give 2, 3, 5, 6, 7, 8, 8a-heptahydrothiazolo-[3,2-a]-s-triazine-5, 7-diones (IIa-e). Preliminary reports indicate some activity of these compounds against Walker's carcinosarcoma 256 in rats. 相似文献
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研究了不活泼芳胺(杂环胺)与α,α-二氰基二硫缩醛的加成-消除反应,报道了一种应用阴离子交换树脂有效合成3-芳氨基-4-氰基-5-氨基吡唑的一锅煮方法。 相似文献
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S. P. Stanforth 《Journal of heterocyclic chemistry》1987,24(2):531-532
Treatment of 1-(2′-nitrophenyl)isoquinoline with hot triethylphosphite afforded indazolo[3,2-a]isoquino-line. 相似文献
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《合成通讯》2013,43(14):2245-2253
ABSTRACT The novel 2-thioxohydantoin ketene S,S-acetals 3a,b were prepared by the reaction of 2-thioxohydantoins 1a,b with carbon disulfide, followed by alkylation with methyl iodide of the produced sodium dithiolate salts 2a,b. The reaction of compounds 3a,b with nucleophiles afforded different fused methylsulfanylimidazoles. 相似文献
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An efficient one‐pot synthesis of pyrido[1,2‐a]‐fused 1,3‐diazaheterocyclic compounds by three‐component reaction of diamine, nitroketene dithioacetal (=1,1‐bis(methylsulfanyl)‐2‐nitroethene), and electron‐poor itaconic anhydride (=2‐methylidenesuccinic anhydride=2‐methylidenebutanedioic anhydride) in aqueous EtOH is reported. This protocol has the advantages of easiness, higher yields, and shorter reaction times. The structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2). 相似文献
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On irradiation with sunlight N-α-cyanoamines (I) undergo a novel cyclisation with the induction of one methylene group from the solvent (methanol) to give new benzoimidazoloquinolines (II) in good yield. 相似文献
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2-Hydroxy-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-one 2a and 7-hydroxy-5H-thiazolo[3,2-a]pyrimidin-5-one 2b, were obtained in high yields under mild conditions from the cyclization reactions of bis-(2,4,6-trichlorophenyl) malonate and 2-aminobenzothiazole or 2-aminothiazole, respectively. A new class of compounds, 2,3-dihydro-4H-benzo[4,5]thiazolo[3,2-a]furo[2,3-d]pyrimidin-4-ones and 6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-ones, were synthesized via the microwave assisted radical addition of compounds 2a and 2b to various alkenes using manganese(III) acetate. A preliminary acetylcholine esterase (AchE) inhibition test of compound 4e showed excellent (92%) inhibitory potential, comparable with the standard drug Donapezil®. 相似文献
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A new synthetic strategy for the synthesis of novel 3-(3-(3-methyl-4-nitroisoxazol-5-yl)-2-phenyl-1-(5,7-diaryl-7H-thiazolo[3,2-a]pyrimidin-3-yl)propyl)-5,7-diaryl-7H-thiazolo[3,2-a] pyrimidines(7a-i) analogues is described.Reaction of 3-(2(3-methyl-4-nitroisoxazole-5-yl)-1-phenylethyl)pentane-2,4-dione(3) with two moles of thiourea in presence of iodine and CuO afforded 4-(1-(2-aminothiazol-4-yl)-3-(3-methyl-4-nitroisoxazol-5-yl)-2-aryl propyl-thiazol-2-amine(5).Compound 5 on reaction with two moles of chalcone(6) furnished novel 3-(3-(3-methyl-4-nitroisoxazol-5-yl)-2-phenyl-1-(5,7-diaryl-7H-thiazolo[3,2a]pyrimidin-3-yl)propyl)-5,7-diaryl-7H-thiazolo[3,2-a] pyrimidines(7a-i). 相似文献
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Condensation of 2-amino-4-hydroxy-2-mercaptopyrimidine (2) hydrate and ethyl 4-bromocrotonate gave a mixture of ethyl 7-amino-2,3-dihydro-5-oxo-5H-thiazolo[3,2-a]pyrimidine-3-acetate (4) and 2a,3-dihydro-1-thia-5,8,8b-triazaacenaphthylene-4,7(2H)-dione (5) whereas reaction of 2 with 4-bromocrotononitrile afforded only 7-amino-2,3-dihydro-5-oxo-5H-thiazolo[3,2-a] pyrimidine-3-acetonitrile. Reaction of the tricycle 5 (which was isolated as a hemihydrate) with excess methyl iodide/potassium carbonate in dimethylformamide resulted in both ring hydrolysis and methylation to give 3,4-dihydro-1,7-dimethyl-4- [(methylthio)methyl]-2H-pyrimido[1,6-a]pyrimidine-2,6,8(1H,7H)-trione (10). Methylating 5 with excess methyl iodide/sodium methoxide in methanol also resulted in ring fragmentation and methylation but instead afforded methyl 7-methyl-amino-2,3-dihydro-5-oxo-7H-thiazolo[3,2-a]pyrimidine-3-acetate. The mechanistic aspects of these reactions are discussed. 相似文献
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Reaction of 2-aminothiazoline with an aromatic aldehyde and an activated methylene group (malonitrile, diethylmalonate or ethylcyanoacetate) gave the title compounds. The structures are unambiguously assigned using spectroscopic data and chemical proofs. 相似文献
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Ahmed M. M. Hassan El-Sayed A. M. Badawey 《Monatshefte für Chemie / Chemical Monthly》1991,122(1-2):43-46
Summary The syntheses of 1,3,4-oxadiazolo[3,2-a]-s-triazine-5,7(6H)-diones4 through the condensation of 2-amino-5-aryl-1,3,4-oxadiazoles1 with ethoxycarbonyl isocyanate2 is described. Methylation of4b with trimethyl phosphate yielded the N-methyl derivative5.
Kondensierte Ringsysteme des Oxadiazols, 2. Mitt. [1]: Synthese von neuen 2-Aryl-1,3,4-oxadiazolo[3,2-a]-s-triazin-5,7(6H)-dionen
Zusammenfassung Die Synthese von 1,3,4-Oxadiazolo[3,2-a]-s-triazin-5,7(6H)-dionen4 durch Kondensation von 2-Amino-5-aryl-1,3,4-oxadiazolen1 mit Ethoxycarbonylisocyanat2 wird beschrieben. Die Methylierung von4b mit Trimethylphosphat gibt das N-Methyl-Derivat5.相似文献
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V. N. Britsun A. N. Esipenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2006,42(3):396-402
We have studied the reaction of 2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-one and 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones
with amines, alkylating reagents, and hydrogen peroxide. We have shown that the presence of an aryl substituent at the 2 position
of [1,3-thiazino[3,2-a]benzimidazol-4-ones has a substantial effect on the direction of the reactions.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 445–452, March, 2006. 相似文献
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