Synthesis, biological activity and crystal structure of ethyl 6-amino-8-(4-methoxy phenyl)-9-nitro-2,3,4,8-tetrahydropyrido[2,1b][1,3]thiazine-7-carboxylate

Abstract

The compound ethyl 6-amino-8-(4-methoxy phenyl)-9-nitro-2,3,4,8-tetrahydropyrido[2,1b][1,3]thiazine-7-carboxylate (C14H22N4O4S2) has been synthesized by multicomponent reactions, and characterized by 1H NMR, IR, and X-ray diffraction. The crystal structure analysis shows that the thiazinane ring displays a half-chair conformation. The benzene ring is almost vertical to the tetrahydro-pyridine ring. Intramolecular H-bonding of N–H···O type exists and completes an S (6) ring. In the crystal, the molecules are connected into a 3D network by a N–H···O and C–H···O intermolecular hydrogen bond. The bioassay indicates that the compound shows moderate insecticidal activity against Aphis craccivora.