CRYSTALLOGRAPHIC STUDY OF 3 CORONARY VASODILATORS OF THE NITRATE ESTER-TYPE - 1,4-TRANS-CYCLOHEXANEDIMETHANOL DINITRATE, 1,4 3,6-DIANHYDRO-D-GLUCITOL-2,5-DINITRATE AND 1,4/3,6-DIANHYDRO-D-GLUCITOL-2-MONONITRATE/

The crystal structures of three vasodilators of the nitrate ester type have been determined by X-ray diffraction. Compound 1, 1,4-trans-cycl ohexanedimethanol dinitrate (CDDN), C8H14N2O6, is a recently developed nitrate ester with a promising haemodynamic profile in the treatment of ischaemic heart diseases. CDDN crystallizes in space group P2(1)/a with a = 5.9443(4), b = 16.7052(9), c = 6.2022(2) angstrom, beta = 116 .669(4)-degrees, Z = 2 and T = 295 K. The molecule lies on a centre of inversion and the structure refined to R = 0.042 for 991 reflections with I > 2.5sigma(I). The cyclohexane ring approaches an ideal chair c onformation and the C-0-NO2 fragment is strictly planar. Compound 11 i s the widely applied vasodilator in angina pectoris, isosorbide dinitr ate or 1,4:3,6-dian-hydro-D-glucitol-2,5-dinitrate (ISDN), C6H8N2O8. I SDN crystallizes in space group P22(1)2(1) with a = 5.7535(2), b = 10. 9393(5), c = 14.6599(5) angstrom, Z = 4 and T = 295 K. The structure r efined to R = 0.033 for 1104 reflections with I > 2.5sigma(I). The mol ecular skeleton consists of two cis-fused five-membered rings, which e ach adopt an envelope conformation such that the torsion angles about the central C-C bond are 0.3(2) and -7.8(2)-degrees. The angle between the rings is 60.8(1)-degrees and the two nitrate groups are planar. C ompound III, isosorbide-2-mononitrate or 1,4:3,6-dianhydro-D-glucitol- 2-mononitrate (IS-2MN), C6H9NO6, is an active metabolite of II and cry stallizes in space group P2(1)2(1)2(1) with a = 6.4318(4), b = 7 5273( 4), c = 15.866(1) angstrom Z = 4 and T = 100 K. The structure refined to R = 0.031 for 1488 reflections with I > 2.5sigma(I). The skeleton o f III is very similar to that of II. The torsion angles about the cent ral C-C bond are 2.4(2) and 3.1(2)-degrees, the interplanar angle is 6 1.5(1)-degrees and the nitrate group is strictly planar.