X-ray mapping in heterocyclic design: 17. Crystal and molecular structures of the “molecule of the month”; and its hydrogenated form

The structures of 2,8-dimethyl-5-[2-(6-methylpyridin-3-yl)ethyl]-2,3,4,4a,5,9b-hexahydro1H-pyrido[4,3-b]indole trihydrobromide (I) (a = 12.865(4) Å, b = 14.281(3) Å, c = 13.553(3) Å, Z = 4, sp. gr. Pna21) and 2,8-dimethyl-5-[2-(6-methylpyridin-3-yl)ethyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole dihydrobromide (II) (a = 13.9704(14) Å, b = 14.4447(15) Å, c = 10.7819(12)Å, β = 107.58(1)°, Z = 4, sp. gr. P21/c) were studied by single-crystal X-ray diffraction. The structures were solved by direct methods and refined by the full-matrix least-squares method with anisotropic displacement parameters to the R factors of 0.0603 and 0.0446, respectively. All Br− anions form hydrogen bonds with protonated nitrogen atoms. The synthesis and physicochemical parameters of these two compounds are reported.