N-(X-Methylphenyl)-2-{(Z)-[(2,3,4-trimethoxyphenyl)methylidene]amino}-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide, where X = 2 and 3.
The title isomers, viz. the N-(3-methylphenyl)-, (I), and N-(2-methylphenyl)-, (II), derivatives, both C(26)H(28)N(2)O(4)S, adopt an E configuration that places the thiophene and trimethoxyphenyl groups on opposite sides of the C=N double bond, providing a suitable orientation for formation of an intramolecular N-H...N hydrogen bond. However, while the molecule in (I) is close to being planar, the N-methylphenyl group in (II) is twisted significantly from the plane of the remainder of the molecule. Both crystal structures are essentially layered and there are no intermolecular N-H...O hydrogen bonds. Compound (I) has a significantly higher calculated density than (II) (1.340 cf 1.305 Mg m(-3)), indicating that the molecular packing in the meta isomer is overall more efficient than that in the ortho isomer.
Harvard Degree College, Nelamangala Road, Bangalore 562 126, Karnataka, India.
Govindaiah
G
Darshan
Deepak
D
Chopra
Janardhanan
J
Saravanan
D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D015394:Molecular Structure; D013876:Thiophenes / Q000737:chemistry*
C554874:N-(2-methylphenyl)-2-((Z)-((2,3,4-trimethoxyphenyl)methylidene)amino)-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide; D013876:Thiophenes