Molecular and crystal structures of two 1,2,4-benzothiadiazine derivatives

Abstract

The synthesis of two 1,2,4-benzothiadiazine derivatives, namely, 6-bromo-4H-spiro[1,2,4-benzothiadiazine- 3,1′-cyclobutane] 1,1-dioxide (1) and 6-bromo-1′-ethyl-4H-spiro[1,2,4-benzothiadiazine-3,4′- piperidine] 1,1-dioxide (2) is described in the present work. The synthesized compounds were studied by IR, 1H and 13C NMR, and single crystal X-ray diffraction to determine their molecular and crystal structure. In both structures the conformation of the 1,2,4-thiadiazinane ring is a twisted chair and is stabilized by the intramolecular interaction of the C–H…O type. Compound 1 crystallizes in the monoclinic crystal system and space group C2/c with the unit cell parameters a = 15.8690(17) A, b = 12.1453(16) A, c = 12.0152(15) A, β = 99.686(7)°, Z = 8 and V = 2282.7(5) A3. Compound 2 crystallizes in the monoclinic crystal system and space group P21/c with the unit cell parameters a = 14.5748(6) A, b = 9.3340(5) A, c = 12.4283(6) A, β = 112.757(2)°, Z = 4 and V = 1559.14(13) A3. In the crystal structures different packing motifs are implemented with the formation of supramolecular assemblies of different types due to classical hydrogen bonds such as N–H…O and intermolecular interactions of N–H…Br, N–H…N, C–H…O types and π…π stacking.