Mohammed B. Alshammari

Comparison of cyclic and polymeric disulfides as catalysts for the regioselective chlorination of phenols

Two cyclic and two polymeric disulfides have been synthesized and established to be useful catalysts for the chlorination of m-xylenol, o-cresol, m-cresol and phenol using freshly distilled sulfuryl chloride in the presence of aluminum or ferric chloride as a co-catalyst at room temperature. The yields of p-isomers and para/ortho ratios were higher compared to cases where no catalyst was used with most catalysts for most phenols even when a very low concentration of disulfide was used. GRAPHICAL ABSTRACT

Crystal structure of 4-methyl­sulfanyl-2-phenyl­quinazoline

In the title compound, C15H12N2S, the methylthioquinazoline group is planar with the methyl C displaced by only 0.116 (3) Å from the plane of the quinazoline moiety. The dihedral angle between the phenyl ring and the quinazoline ring system is 13.95 (5)°. In the crystal, each molecule is linked by π–π stacking between to two adjacent inversion-related molecules. On one side, the inverted quinazoline groups interact with a centroid–centroid distance of 3.7105 (9) Å. On the other side, the quinazoline group interacts with the pyrimidine and phenyl rings of the second neighbour with centroid–centroid distances of 3.5287 (8) and 3.8601 (9) Å, respectively.

1-(2-Bromo-4-methylphenyl)-3,3-dimethylthiourea

The bromomethylphenyl and dimethylthiourea groups of the molecule of the title compound, C10H13BrN2S, are inclined to one another at an interplanar angle of 55.13 (6). In the crystal, molecules are stacked along the b axis and intermolecular N—HS contacts form chains of molecules along [010]. St

Methyl N-(2-bromo-4-chlorophenyl)carbamate

In the title molecule, C8H7BrClNO2, the bromochlorophenyl ring is inclined to the methylcarbamate unit by 32.73 (7). In the crystal, N—HO hydrogen bonds form chains of molecules parallel to [100].

Crystal structure of 3-(4-chlorophenyl)-1,1-dimethylthiourea, C9H11ClN2S

Abstract C9H11ClN2S, monoclinic, Pc (no. 7), a = 14.8440(4) Å, b = 7.2002(2) Å, c = 10.0920(2) Å, β = 99.733(2)°, V = 1063.10(5) Å3, Z = 4, Rgt(F) = 0.0399, wRref(F2) = 0.1099, T = 296(2) K.

Crystal structure of 4-meth­oxy­quinazoline

The title compound, C9H8N2O, is almost planar, with the C atom of the methoxy group deviating from the mean plane of the quinazoline ring system (r.m.s. deviation = 0.011 Å) by 0.068 (4) Å. In the crystal, molecules form π–π stacks parallel to the b-axis direction [centroid–centroid separation = 3.5140 (18) Å], leading to a herringbone packing arrangement.

Crystal structure of 4,4-dibutyl-2-phenyl-3,4-di-hydro-quinazoline.

In the title compound, C22H28N2, the dihedral angle between the planes of the phenyl ring and the dihydroquinazoline ring system (r.m.s. deviation = 0.030 Å) is 24.95 (7)° and both n-butane chains assume all-trans conformations. In the crystal, N—H⋯N hydrogen bonds link the molecules into C(4) chains propagating in the [001] direction.