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21.
Paola Acosta Braulio Insuasty Rodrigo Abonia Margarita Gutierrez Jairo Quiroga 《Molecular diversity》2017,21(4):943-955
An efficient route for the synthesis of novel 7-aryl and 7-spiropyrazolo[4\(^{\prime }\),3\(^{\prime }\):5,6]pyrido[2,3-d]pyrimidine derivatives is described. These compounds were obtained by a cyclocondensation reaction between pyrazolopyridinediamines 4 and aldehydes 5 or cyclic ketones 6 in the presence of acetic acid as catalyst. This procedure provides the desired compounds in good yields under a simple two-step methodology. The obtained compounds were evaluated as AChE inhibitors and showed weak AChe inhibition with \(\hbox {IC}_{50} = 115{-}470 \, \upmu \hbox {M}\). 相似文献
22.
23.
Braulio Insuasty Yupanqui Caldfas Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):o483-o486
The molecules of the title compound, C20H23N3O6, are almost completely planar, apart from the H atoms bonded to tetrahedral C atoms. A combination of five hydrogen bonds, one of the N—H...O type and two each of the C—H...O and C—H...π(arene) types, links the molecules into complex sheets. 相似文献
24.
Rivero-Chan BE Marrero JG Hernández-Ortega S Mena-Rejón GJ Miranda LD 《Natural product research》2012,26(7):675-679
We describe in this article a process with which to obtain different ketones related to oleanolic and ursolic acids from a natural source, Salvia canariensis L., with minimal use of chromatography columns. Amongst the isolated compounds was 12α-bromo-3-oxo-olean-13, 28-olide (3), which was fully characterised, including a characterisation of its molecular configuration by X-ray crystallographic analysis by 1 and 2-dimensional NMR techniques. 相似文献
25.
López JL Atienza C Insuasty A López-Andarias J Romero-Nieto C Guldi DM Martín N 《Angewandte Chemie (International ed. in English)》2012,51(16):3857-3861
Chromophore-peptide systems: a study on a series of pentapeptides covalently connected to planar π systems (1 a and 1 b) or to a curved π system (1 c) showed the influence of the concave shape on the efficient chiral transmission at nano- and mesoscales. Control over the hierarchical growth by H bonding, π-π, and solvophobic interactions made possible the efficient generation of electroactive 3D helical fibers. 相似文献
26.
Fraga BM Guillermo R Hernández MG Chamy MC Garbarino JA 《Molecules (Basel, Switzerland)》2012,17(2):1744-1750
The biotransformation of 13α,17-dihydroxystemodane (3) with the fungus Cephalosporium aphidicola afforded 13α,17,18-trihydroxystemodane (4), 3β,13α,17-tri-hydroxystemodane (5), 13α,17-dihydroxy-stemodan-18-oic acid (6), 3β,11β,13α,17-tetra-hydroxystemodane (7), 11β,13α,17,18-tetrahydroxystemodane (8) and 3β,13α,17,18-tetra-hydroxystemodane (9). The hydroxylation at C-18 of the substrate points to a biosynthetically-directed transformation, because aphidicolin (2) is hydroxylated at this carbon. However, the C-3(β) and C-11(β) hydroxylations seem to indicate a xenobiotic biotransformation. 相似文献
27.
Jairo Quiroga Braulio Insuasty Henry Insuasty Rodrigo Abonia Antonio Ortíz Adolfo Snchez Manuel Nogueras 《Journal of heterocyclic chemistry》2001,38(2):339-341
Benzo[h]pyrimido[4,5‐b]quinolines ( 3 ) have been synthesized via a regiospecific cyclocondensation reaction between 6‐aminopyrimidines ( 1 ) and 2‐dimethylaminomethylentetralone hydrochloride ( 2 ). The linear structure of the final compounds were determined by nmr measurements, especially by 1H,1H, 1H,13C COSY and DEPT experiments. 相似文献
28.
Insuasty O. Braulio Insuasty I. Henry Quiroga P. Jairo Claudio Saitz Carolina Jullian 《Journal of heterocyclic chemistry》2000,37(2):401-403
Several new 6‐amino‐ and 6,8‐diamino‐4‐aryl‐2,3‐dihydropyrimido[4,5‐b][1,4]diazepines were obtained from the reaction of 4,5,6‐triaminopyrimidine 1a and 2,4,5,6‐tetraaminopyrimidine 1b with one equivalent of 3‐dimethylaminopropiophenones 2 in absolute ethanol. Structure analysis of 6‐amino‐ and 6,8‐diamino‐4‐aryl‐2,3‐dihydropyrimido[4,5‐b][1,4]diazepines 3a‐i , determined by detailed nmr measurements, reveals a high regioselectivity of this reaction. 相似文献
29.
Jairo Quiroga Mario Alvarado Braulio Insuasty Manuel Nogueras Adolfo Snchez M. Dolores Lpez 《Journal of heterocyclic chemistry》1999,36(1):113-115
The title compounds 4 and 5 have been prepared in one-step reaction from 6-amino-4-pyrimidinones 1 , the corresponding 4-substituted benzaldehyde 2 and ethyl cyanoacetate 3 in very good yields. The structure of the final compounds was determined on the basis of nmr measurements, especially by 1H, 1H-, 1H,13C COSY, and DEPT. 相似文献
30.
Jairo Quiroga Mario Alvarado Braulio Insuasty Rodolfo Moreno Enrique Ravia Isabel Estevez Regina H. De Almeida S. 《Journal of heterocyclic chemistry》1999,36(5):1311-1316
This paper describes the synthesis of a new series of 6-amino-4-aryl-5-cyanopyrazolo[3,4-b]pyridines 4 and 4-aryl-5-cyano-6H-pyrazolo[3,4-b]pyridin-6-ones 5 from the reaction of 5-amino-3-methyl-1-phenylpyrazole 1 with arylidene derivatives of malonodinitrile 2 and ethyl cyanoacetate 3 . The structure of the final compounds was determined on the basis of nmr measurements, especially by 1H, 1H-, 1H, 13C-COSY, DEPT and X-ray diffraction. 相似文献