In the crystal structure of the title mol-ecule, C(13)H(15)NO(5)S, the S and N atoms of the thia-zine ring exihibit the maximum deviations from the least-squares plane of 0.3008 (6) and 0.3280 (7) Å, respectively. The ring therefore adopts a half chair conformation. The thia-zine ring is twisted by an angle of 13.29 (7)° with respect to the aromatic ring. The isopropyl substituent is oriented a...

In the title compound, C(16)H(22)N(2)OS(2), the S atom of the thia-diazole ring and the attached methyl groups are disordered over two orientations with a refined site-occupancy ratio of 0.641 (11):0.359 (11). The thia-diazole ring is in a twist conformation in both disorder components. The mean plane through the thia-diazole ring makes dihedral angles of 77.39 (8) (major component) and 67.45 (...

In the title compound, C(22)H(29)N(3)O(5)S, the pyrrolidine ring is cis-fused to the dihydro-pyran ring. The pyrrolidine and dihydro-pyran rings adopt twist and half-chair conformations, respectively. The mol-ecule is in a folded conformation; the sulfonyl-bound benzene ring lies over the pyrimidine-dione ring, with a weak π-π inter-action [centroid-centroid distance = 3.6147 (4) Å]. A weak int...

The title compound, C(18)H(14)FN(3)O(2)S(2), was synthesized by the reaction of 5-(4-fluoro-phen-yl)-N-(4-methoxy-benzyl-idene)-1,3,4-thia-diazol-2-amine and mercaptoacetic acid. The thia-zolidinone ring adopts a twist conformation. The 4-methoxy-phenyl ring is almost perpendicular to the thia-diazole ring, making a dihedral angle of 88.4 (3)°. The 4-fluoro-phenyl ring is nearly coplanar with t...

The title compound, C16H13N3OS, comprises an oxa-diazo-lethione ring bound to the N atom of an almost planar carbazole ring system (r.m.s. deviation = 0.0088 Å) through an ethyl-ene chain. The oxa-diazole ring is inclined to the the carbazole ring system by 40.71 (6)°. In the crystal, N-H⋯O, N-H⋯S, C-H⋯N and C-H⋯S hydrogen bonds combine with C-H⋯π(ring) and π-π contacts to stack the mol-ecules ...

In the title compound, C(22)H(24)ClN(3)O(4), intra-molecular C-H⋯O and C-H⋯N hydrogen bonds form S(9) and S(7) ring motifs, respectively. The 1,4-dihydro-pyridine ring adopts a flattened boat conformation. The benzene ring makes a dihedral angle of 33.36 (6)° with the pyrazole ring. In the crystal, pairs of N-H⋯N hydrogen bonds link the mol-ecules into inversion dimers. The dimers are stacked i...

In the title compound, C(19)H(16)N(6)O(3)S, the 3,6-dihydro-1,3,4-thia-diazine ring adopts a twist-boat conformation. The dihedral angle between the meth-oxy-substituted benzene ring and the oxadiazole ring is 71.91 (7)°. In the crystal structure, centrosymmetrically related mol-ecules are linked into dimers via pairs of inter-molecular N-H⋯N hydrogen bonds, generating R(2) (2)(8) ring motifs. ...

In the racemic title compound, C(15)H(19)NO(3)S, the dihedral angle between the planes of the benzene ring and the O=S=O group is 56.92 (7)° and the cyclo-hexane ring adopts a chair conformation.

thirty nine novel 1,2,3,4-tetrahydropyrimidinone (thione)s were subjected to conformational studies. density functional theory at b3lyp/6-31 g* was performed as the computational method of high accuracy. important dihedral angles and bond lengths were investigated and the values obtained were explainable. results of this work confirm a twisted boat tetrahydropyrimidine ring conformation with an...

In the title compound, C(20)H(22)N(2)S(2), the five-membered thia-zole ring of the 2-methyl-2,3-dihydro-1,3-benzothia-zole unit has an envelope conformation. The dihedral angle between the planar [maximum deviation of 0.014 (1) Å for the S atom] benzothia-zole ring system and the benzene ring is 78.37 (12)°. Two intra-molecular C-H⋯S hydrogen bonds are observed, forming rings of graph-set motif...