Synthesis and crystal structure of lappaconitine hydrobromide

A method for the synthesis of lappaconitine hydrobromide by the reaction of dibromoalkyl with lappaconitine is presented. Lappaconitine hydrobromide was determined by IR, C-13 NMR, HRMS spectra, elemental analysis and X-ray diffraction analysis. Through intermolecular hydrogen bonding, the similar super molecule netlike structure is formed. Crystal data: monoclinic, P2(1), a= 1.0619(2) nm, b = 1.2196(3) nm, c = 1.2282(2) nm, ss= 90.87(1)degrees, V= 1.59037(54) nm(3), Z= 2, D-m = 1.428 g/cm(-3), F(000)=720.0, mu = 1.349 mm(-1) Rings A, B, C, D, E and F present boat, chair, envelope, boat, boat and envelope forms, respectively. The stereo absolute configuration of lappaconitine hydrobromide was determined as 1S,4S,5S,7S,8S, 9S, 10S, 11S, 13R, 14S, 16S, 17R.