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51.
52.
Jairo Quiroga Braulio Insuasty Angelina Hormaza Claudio Saitz Carolina Jullian 《Journal of heterocyclic chemistry》1998,35(3):575-578
Reaction of 5-amino-3-methyl-1-phenylpyrazole ( 1a ) and 5-amino-3-(4-chlorophenyl)-1H-pyrazole ( 1b ) with dimedone ( 2 ) and p-susbstituted benzaldehydes 3 in ethanol, afforded in all cases tricyclic linear 4-aryl-7,7-dimethyl-4,7,8,9-tetrahydro-6H-pyrazolo[3,4-b]quinolin-5-ones ( 4a-j ) in good yields. The linear structures and hence the regiospecificity of the reaction were established by nmr measurements. 相似文献
53.
A series of 5-amino-1-aroylpyrazoles 3 are synthesized directly by the reaction of β-aminocrotononitrile 1 with some structures containing the hydrazine moiety (X-NHNH2) 2 by refluxing ethanol in presence of sodium acetate. When semicarbazide 3i was used (X = CONH2), the reaction afforded the unexpected 7-aminopyrazolo[1,5-a]pyrimidine 4. 相似文献
54.
E Escalante-Sánchez B Rodríguez-Molina MA Garcia-Garibay 《The Journal of organic chemistry》2012,77(17):7428-7434
A strategy for the construction of crystalline molecular rotors involves the assemblage of chemical structures that emulate the elements of macroscopic rotary devices, such as those found in macroscopic gyroscopes and compasses. In this report, we describe an efficient and short synthetic route for preparation of molecular rotors with two pentiptycene-units linked at their central benzene ring by triple bonds to a linearly conjugated phenylene rotator. Five analogous compounds with phenol, alkoxy, or alkoxycarbonyl substituents were synthesized and fully characterized in solution and in the solid-state through various methods, such as cross-polarization magic angle spinning (CPMAS) (13)C NMR and single crystal X-ray diffraction. Molecular and packing structures obtained from single crystal X-ray diffraction and crystallization properties were analyzed with the goal of identifying the key parameters that may hinder or facilitate the formation of dynamically functional, crystalline molecular rotors. 相似文献
55.
Valentine MT Guydosh NR Gutiérrez-Medina B Fehr AN Andreasson JO Block SM 《Optics letters》2008,33(6):599-601
We designed, constructed, and tested a single-beam optical trapping instrument employing twin electro-optic deflectors (EODs) to steer the trap in the specimen plane. Compared with traditional instruments based on acousto-optic deflectors (AODs), EOD-based traps offer a significant improvement in light throughput and a reduction in deflection-angle (pointing) errors. These attributes impart improved force and position resolution, making EOD-based traps a promising alternative for high-precision nanomechanical measurements of biomaterials. 相似文献
56.
Braulio Insuasty O Henry Insuasty I Jairo Quiroga P Claudio Saitz Carolina Jullian 《Journal of heterocyclic chemistry》1999,36(3):635-638
New 4-Aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines were obtained from the reaction of 4,5-diamino-3-methyl-1-phenylpyrazole 1 with one equivalent of the 3-dimethylaminopropiophenones 2 in absolute ethanol. The structures of 4-aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines 3 and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines 4 were determined by detailed nmr measurements. 相似文献
57.
58.
Alba Montoya Braulio Insuasty Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(7):677-680
In the title compound, C26H20ClNO3, the quinoline fragment is nearly orthogonal to the adjacent aryl ring, while the rest of the molecular skeleton is close to being planar. The crystal structure contains no hydrogen bonds of any sort, but there are two π–π stacking interactions present. One, involving the quinoline ring, links molecules related by inversion, while the other, involving the two nonfused aryl rings, links molecules related by translation, so together forming a ladder‐type arrangement 相似文献
59.
S. Vianna-Rodrigues L. Martins-Viana J. Quiroga B. Insuasty R. Abonia W. Baumann 《Journal of heterocyclic chemistry》1994,31(4):813-817
The separation of the two regioisomeric derivatives of 1H-1,5-benzodiazepine yielded from the reaction of 1,2-diamino-4-methylbenzene with 4-substituted acetophenones was performed by reversed phase high performance liquid chromatography, and the absorption spectra of the separated isomers have been determined for three isomer pairs which have been obtained starting from acetophenones with substituents of different electronegativity. The isomer ratio then could be estimated as well from the ratio of the peak areas as from the absorption spectra. They agree well with the known ratio determined from nmr intensities. 相似文献
60.
Braulio Insuasty Ricaurte Rodriguez Jairo Quiroga Roberto Martinez Enrique Angeles 《Journal of heterocyclic chemistry》1997,34(4):1131-1133
The acid catalyzed condensation of 4,5-diaminopyrazoles and chalcones gave the hitherto unknown 1-benzyl-2,4,6-triphenyl-2,3-dihydropyrazolo[3,4-b][1,4]diazepines derivatives. The structure of all products was supported by ir, 1H and 13C-nmr and mass spectra. 相似文献