N-[4-Acetyl-5-(3-methoxy­phen­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

The title compound, C13H15N3O3S, crystallizes with two mol­ecules in the asymmetric unit. The thia­diazole rings in both the mol­ecules adopt an envelope conformation. The crystal packing is stabilized by inter­molecular N—H⋯O and C—H⋯O inter­actions

Dimethyl 2-(3-chloro­phen­yl)-6-hy­droxy-6-methyl-4-(methyl­amino)­cyclo­hex-3-ene-1,3-dicarboxyl­ate

In the title compound, C18H22ClNO5, the cyclo­hexene ring adopts a distorted half-chair conformation. The mol­ecular structure is stabilized by pairs of intra­molecular N—H⋯O and O—H⋯O inter­actions, generating S(6) motifs. In the crystal, the mol­ecules are linked by inter­molecular C—H⋯O inter­actions, forming centrosymmetric dimers

2,4-Bis(4-bromo­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

The title compound, C20H19Br2NO, shows a chair–chair conformation for the aza­bicycle with an equatorial disposition of the 4-bromo­phenyl groups [dihedral angle between the aromatic rings = 16.48 (3)°]. In the crystal, a short Br⋯Br contact [3.520 (4) Å] occurs and the structure is further stabilized by N—H⋯O hydrogen bonds and C—H⋯O inter­actions

A Study of Internal Pressures of Binary Liquid Mixtures at Different Temperatures

1023-102

N-[(1E)-5-(3-Chlorophenyl)-3-methylcyclohex-2-en-1-ylidene]hydroxylamine

The whole of the title molecule, C13H14ClNO, is disordered over two sets of sites with a refined occupancy ratio of 0.560 (6):0.440 (6). The oxime group having a C=N double bond adopts an E conformation. The dihedral angles between the rings (all atoms) are 89.5 (5) (major componenent) and 88.0 (6)° (minor component)

Ethyl 4-(3-chlorophenyl)-3,6-dihydroxy-6-methyl-2-(2-pyridyl)-4,5,6,7-tetrahydroindazole-5-carboxylate

In the title compound, C22H22ClN3O4, the cyclohexane ring adopts a twisted half-chair conformation. The molecule is stabilized by an intramolecular O—H...N interaction, generating an S(6) motif. The crystal packing is stabilized by intermolecular O—H...N and C—H...O interactions

Isopropyl 1-benzoyl-4-benzoyloxy-2,6-diphenyl-1,2,3,6-tetrahydropyridine-3-carboxylate

In the title compound, C35H31NO5, the piperidine ring has an envelope conformation, with the phenyl-substituted C atom adjacent to the methylene C atom as the flap. This flap atom deviates by 0.633 (2) Å from the mean plane of the other five essentially coplanar atoms in the ring (r.m.s. deviation = 0.044 Å). Intramolecular C—H...O hydrogen bonds form S(7) and S(9) ring motifs. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with R22(16) loops

Synthesis and ¹H and ¹³C NMR spectral study of some t(3)-aryl-r(2),c(4)- dicarbalkoxy-c(5)- hydroxy-t(5)- methylcyclohexanones and their oximes

1004-1013Eight t(3)-aryl-r(2),c(4)-bis(carbalkoxy)-c(5)- hydroxy-t(5)-methylcyclohexanone oximes 4a (Ar = Ph; R = Et), 5a (Ar = p-NO₂C₆H₄; R = Et), 6a (Ar = p-ClC₆H₄; R = Et), 7a (Ar = Ph; R = Me), 8a (Ar = p-NMe₂C₆H₄; R = Me), 9a (Ar = m-NO₂C₆H₄; R = Me), 10a (Ar = p-FC₆H₄; R = Me) and 11a (Ar = p-OMeC₆H₄; R = Me) have been synthesized by treating the corresponding ketones with NH₂OH in the presence of sodium acetate. Ketones 8-11 have been newly synthesized by condensing methyl acetoacetate with the appropriate aromatic aldehyde in presence of methylamine. ¹H and ¹³C NMR spectra of ketones 7, 8, 10 and 11 and oximes 4a, 5a and 6a have been recorded in CDCl₃. ¹H and ¹³C NMR spectra of ketone 9 and the other oximes 7a-11a have been recorded in DMSO-d₆ since they are insoluble in CDCl₃. HOMOCOR spectrum has been recorded for 7 (in CDCl₃) and 7a. NOESY spectrum has been recorded for 4a, 7 (in CDCl₃ and DMSO-d₆), 7a and 8a. HSQC spectrum has been recorded for 7 (in CDCl₃) and 7a. HMBC spectrum has been recorded for 5a and 7a. DEPT spectrum has been recorded for 4a. The observed vicinal coupling constants suggest that all the compounds studied exist largely in chair conformation with axial orientations of the hydroxyl group at C-5 and equatorial orientations of all the other substituents. All the oximes have E configuration about C=N bond. The OH-proton at C-5 prefers to be anti to C(5)-C(6) bond in CDCl₃ but anti to C(4)-C(5) bond in DMSO-d₆. Change of solvent from CDCl₃ to DMSO-d₆ has a marked effect on the chemical shifts of the protons in the cyclohexane ring and OH proton. Among the two methylene protons at C-6 the equatorial proton has a higher chemical shift than the axial proton in CDCl₃ but a reverse trend is observed in DMSO-d₆. However,¹³C chemical shifts are not influenced by the change of solvent. Oximation shields all the ring carbons of the cyclohexane ring except C-4. Oximation shields all the protons in the cyclohexane ring except H-6e, which is deshielded by about 0.9 to 1.0 ppm. Use of ¹H and ¹³C chemical shifts for determining the configuration and conformation of oximes is also discussed