Synthesis and Crystal Structure of Dimethyl-3-（4-bromophenyl）-1-phenyl-4,5-dihydro-1H-pyrazole-4,5-dicarboxylate

The title compound (C19H17BrN2O4) was synthesized via a one-pot procedure starting from 4-bromobenzaldehyde, dimethyl acetylenedicarboxylate (DMAD) and phenylhydrazine with pyridine as the catalyst. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.115(3), b = 8.090(2), c = 20.211(5) , β = 97.032(5)°, V = 1803.7(8) 3, Z = 4, Mr = 417.25, Dc = 1.536 g/cm3, μ = 2.306 mm-1, F(000) = 852, the final R = 0.0403 and wR = 0.0895 for 2215 observed reflections with I 2σ(I).     

Synthesis of 1, 3, 5-trisubstituted-4,5-dihydro-1H-pyrazole catalyzed by vitamin B1 and its fluorescence properties

Research on Chemical Intermediates - An efficient synthesis of 1,3,5-trisubstituted-1H-pyrazoles was developed via cyclocondensation in 78–92% yields starting from α,β-unsaturated...     

Formation and structure of 1-Amino-4-methyl-4-(4-methyl-5-phenyl-1H-pyrazol-3-ylamino)-3-phenyl-4,5-dihydro-1H-pyrazol-5-one

The title compound 3 was obtained during the rearrangement of isoxazol-5-yl hydrazine 1 to 1-aminopyrazolone 2 at 115°. X-ray analysis of the corresponding benzylidene derivative allowed us to achieve the structure assignment.     

Interaction of 5-aryl-4-quinoxalinyl-2,3-dihydro-2,3-furandiones with mesitylamine and methyl(phenyl)hydrazine. Synthesis and crystal and molecular structure of 2-(1-mesityl-4,5-dioxo-2-phenyl-4,5-dihydro-3-pyrollyl)-3-phenylquinoxaline

The interaction of 5-aryl-4-quinoxaline-2,3-dihydro-2,3-furandiones with mesitylamine and methyl(phenyl) hydrazine results in the formation of 1-substituted 5-aryl-4-quinoxalinyl-2,3-dihydro-2,3-pyrrolediones. The crystal and molecular structure of the 1-mesityl-5-phenyl derivative was investigated by X-ray diffraction.Original Russian Text Copyright © 2004 by Z. G. Aliev, N. Yu. Lisovenko, L. O. Atovmyan, and A. N. MaslivetzTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 553–557, May–June 2004.     

Simultaneous two-photon excited fluorescence and one-photon excited phosphorescence from single molecules of an organometallic complex Ir(ppy)3

We report a study of excited-state lifetimes of the phosphorescent organometallic complex Ir(ppy)3 on ensemble and a single-molecule level. With decreasing concentration, an increasingly intense fast component of 3 ns lifetime appears next to the 1.1 mus phosphorescence. Experimental evidence suggests that strong two-photon absorption followed by fluorescence is responsible for the fast lifetime component.     

Recyclization of isopropyl 2-(1-aryl-4,5-dioxo-2-phenyl-4,5-dihydro-1H-pyrrol-3-yl)-2-oxoacetates by the action of thiourea

Russian Journal of Organic Chemistry -     

2-(1-苯基-3-甲基-5-氧代-4-吡唑基)-2-磺基丙酸的合成工艺改进

以依达拉奉,丙酮酸和亚磺酸钠为原料,合成了依达拉奉衍生物2-(1-苯基-3-甲基-5-氧代-4-吡唑基)-2-磺基丙酸,总收率54%,纯度>99.9%,其结构经1H NMR,13C NMR和HR-MS确证。     

Synthesis of 4,5-dihydro-4-methyl-1-phenyl-1,4,5-benzotriazocine-2,3,6(1H) triones

The title compounds, 7a and its 9-chloro analog 7b , were prepared in three steps from methyl N-phenylanthranilates. Thus, methyl N-phenylanthranilate ( 3a ) was treated with oxalyl chloride to yield 2-[(2-chloro-1, 2-dioxoethyl) phenylamino]benzoic acid methyl ester ( 4a ). Treatment of 4a with methylhydrazine gave 2-([2-(1-methylhydrazino)-1,2-dioxoethyl]phenylamino) benzoic acid methyl ester ( 6a ), which was cyclized with sodium hydride in dimethylformamide to produce 7a . Alkylation of 7a and 7b with iodomethane afforded the respective 5-methyl derivatives 8a and 8b . A survey of the known literature benzotriazocines is presented.