Crystal and Molecular Structures of Two 2-Aminothiophene Derivatives

Abstract

The crystal and molecular structures of two 2-aminothiophene derivatives, potential allosteric enhancers at the human A1 adenosine receptor, are reported. (2-Amino-4,5,6,7-tetrahydro-1-benzothiophen-3-yl)(phenyl)methanone (1) crystallizes in the orthorhombic space group Pna21 (a = 9.2080(4) Å, b = 14.0485(7) Å, c = 10.3826(6) Å), and (2-amino-5-ethylthiophen-3-yl)(2-chlorophenyl)methanone (2) crystalizes in the monoclinic P21/c space group with unit cell parameters a = 10.6092(8) Å, b = 10.8355(8) Å, c = 11.1346(9) Å, β = 98.643(6)Å. In both molecules the intramolecular N-H***O=C hydrogen bonds close six-membered planar rings and significantly influence the molecular conformation. Intermolecular N-H***O bonds connect the molecules in infinite chains along a in case of 1, and along b in 2; in each case the appropriate unit cell axis is approximately 10 Å long.