Crystal structures of two new isocoumarin derivatives: 8-amino-6-methyl-3,4-diphenyl-1 H -isochromen-1-one and 8-amino-3,4-diethyl-6-methyl-1 H -isochromen-1-one

• Published in: Acta crystallographica. Section E, Crystallographic communications Crystallographic communications, 2019-08, Vol.75 (Pt 8), p.1117-1122
• Main Authors: Syed Abuthahir, S, NizamMohideen, M, Mayakrishnan, S, Uma Maheswari, N, Viswanathan, V
• Format: Article
• Language: English
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989019009435

The title compounds, 8-amino-6-methyl-3,4-diphenyl-1 -isochromen-1-one, C H NO , (I), and 8-amino-3,4-diethyl-6-methyl-1 -isochromen-1-one, C H NO , (II), are new isocoumarin derivatives in which the isochromene ring systems are planar. Compound II crystallizes with two independent mol-ecules ( and ) in the asymmetric unit. In I, the two phenyl rings are inclined to each other by 56.41 (7)° and to the mean plane of the 1 -isochromene ring system by 67.64 (6) and 44.92 (6)°. In both compounds, there is an intra-molecular N-H⋯O hydrogen bond present forming an (6) ring motif. In the crystal of I, mol-ecules are linked by N-H⋯π inter-actions, forming chains along the -axis direction. A C-H⋯π inter-action links the chains to form layers parallel to (100). The layers are then linked by a second C-H⋯π inter-action, forming a three-dimensional structure. In the crystal of II, the two independent mol-ecules ( and ) are linked by N-H⋯O hydrogen bonds, forming chains along the [101] direction. The chains are linked into ribbons by C-H⋯π inter-actions involving inversion-related mol-ecules. The latter are linked by offset π-π inter-actions [inter-centroid distances vary from 3.506 (1) to 3.870 (2) Å], forming a three-dimensional structure.