61 research outputs found
Crystal structure of 1,1-dimethyl-3-(2-phenylethyl)urea, C11H16N2O
Abstract
C11H16N2O, orthorhombic, Pbca (no. 61), a = 10.7388(6) Ă…, b = 9.8449(5) Ă…, c = 21.1259(14) Ă…, V = 2233.5(2) Ă…3, Z = 8, R
gt
(F) = 0.0582, wR
ref
(F
2) = 0.1795, T = 293 K.</jats:p
Highly regioselective dinitration of toluene over reusable zeolite H-beta
A nitration system comprising nitric acid, propanoic anhydride and zeolite H-beta has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4-dinitration of toluene; the catalyst is re-usable, solvent is not needed and an aqueous work-up is not required
Reactions of organolithium reagents with quinazoline derivatives
This review deals with directed and regioselective lithiation of various quinazoline derivatives by the use of alkyllithiums in anhydrous THF at low temperature. Reactions of the lithium reagents obtained from the lithiation reactions with a range of electrophiles give the corresponding substituted derivatives in high yields. The procedures are simple, efficient and general to provide derivatives which might be difficult to produce by other means. In some cases nucleophilic addition of alkyllithiums takes place to produce the corresponding addition products via 1,2- and 3,4-additions. In other cases nucleophilic substitution or halogen-lithium exchange reactions occur
1-(2-Bromo-4-chlorophenyl)-3,3-dimethylthiourea
In the title compound, C9H10BrClN2S, the diÂmethylÂthioÂurea group is twisted from the benzene ring plane by 54.38 (6)°. In the crystal, the amino groups are involved in the formation of N-H***S hydrogen bonds, which link the molÂecules into chains along [010]. Weak C-HCl interÂactions further link these chains into layers parallel to the ab plane
Crystal structure of 3-(2-bromophenyl)-1,1-dimethylthiourea, C9H11BrN2S
C9H11BrN2S, orthorhombic, P212121 (no. 19), a = 7.5187(3) Ă…, b = 8.0634(3) Ă…, c = 17.5320(6) Ă…, V = 1062.90(7) Ă…3, Z = 4, Rgt(F) = 0.0216, wRref(F2) = 0.0536, T = 296(2) K
(E)-2-Benzoyl-3-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]acrylonitrile
The asymmetric unit of the title compound, C23H15N3OS, consists of two crystallographically independent molecules, which are related by a pseudo-inversion centre. In one molecule, the pyrazolyl ring makes dihedral angles of 35.7 (4), 19.1 (1) and 47.3 (1)°, respectively, with the thiophenyl ring, the attached phenyl ring and the phenyl ring of the benzoyl group. In the second molecule, the corresponding values are 37.4 (1), 16.1 (1) and 48.2 (1)°, respectively. In the crystal, the two independent molecules are linked to each other via a π–π interaction between the pyrazolyl rings [centroid–centroid distance = 3.578 (12) Å]. Weak intermolecular C—H...O interactions are also observed. The thiophenyl ring of one molecule is disordered over two orientations, with a refined occupancy ratio of 0.768 (3):0.232 (3)
(E)-1-(4-Bromophenyl)-3-[3-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one
In the title compound, C27H20BrN5O, the dihedral angle between the heterocyclic rings is 10.2 (2)°. The phenyl ring bound to the triazole ring is disordered over two orientations in a 0.808 (4):0.192 (4) ratio. In the crystal, C—H...O interactions form chains along [010]. π–π interactions are observed between the phenyl–pyrazolyl unit and the phenylene group of a neighbouring molecule
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