Central nervous system drugs: Low temperature X-ray structures of (I) the base 5-(2,3-dichlorophenyl)-2,4-diamino-6-fluoromethyl-pyrimidine (4030W92) and (II) 5-(2,6-dichlorophenyl)-1-H-2,4-diamino-6-methyl-pyrimidine methanesulphonic acid salt (227C89)

The X-ray crystal structures of (I), the base 4030W92, 5-(2,3-dichlorophenyl)-2,4-diamino-6-fluoromethyl-pyrimidine, C11H9Cl2FN4, and (II) 227C89, the methanesulphonic acid salt of 5-(2,6-dichlorophenyl)-1-H-2,4-diamino-6-methyl-pyrimidine, C11H11Cl2N4 center dot CH3O3S, have been carried out at low temperature. A detailed comparison of the two structures is given. Structure (I) is non-centrosymmetric, crystallizing in space group P2(1) with unit cell a = 10.821(3), b = 8.290(3), c = 13.819(4) angstrom, beta = 105.980(6)degrees, V = 1191.8(6) angstrom(3), Z = 4 (two molecules per asymmetric unit) and density (calculated) = 1.600 mg/m(3). Structure (II) crystallizes in the triclinic space group P (1) over bar with unit cell a = 7.686(2), b = 8.233(2), c = 12.234(2) angstrom, alpha = 78.379(4), beta = 87.195(4), gamma = 86.811(4)degrees, V = 756.6(2) angstrom(3), Z = 2, density (calculated) = 1.603 mg/m(3). Final R indices [I > 2sigma(I)] are R1 = 0.0572, wR2 = 0.1003 for (I) and R1 = 0.0558, wR2 = 0.0982 for (II). R indices (all data) are R1 = 0.0983, wR2 = 0.1116 for (I) and R1 = 0.1009, wR2 = 0.1117 for (II). 5- Phenyl-2,4 diaminopyrimidine and 6-phenyl-1,2,4 triazine derivatives, which include lamotrigine (3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine), have been investigated for some time for their effects on the central nervous system. The three dimensional structures reported here form part of a newly developed data base for the detailed investigation of members of this structural series and their biological activities.

Convenient synthetic routes to bidentate and monodentate 2-, 3- and 4-pyridyl phosphines: potentially useful ligands for water-soluble complex catalysts

The monodentate and bidentate pyridyl phosphines, PR3 and R2P(CH2)2PR2, where R=3- or 4-pyridyl can be prepared in high yields by treatment of butyllithium/TMEDA/3- or 4-bromopyridine with PCl3 or Cl2P(CH2)2PCl2 at low temperature. 1,2-Bis(di-2-pyridylphosphino)ethane is conveniently synthesised by an alternative route involving reaction of 1,2-dibromoethane with lithium di-2-pyridylphosphide.

Guest editorial. [Computers and Artificial Intelligence. 1998. Vol. 17, No. 2-3]

Editorial

Low temperature X-ray structures of two crystalline forms (I) and (II) of the pyrimidine derivative and sodium channel blocker BW1003C87: 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine

The X-ray crystal structures of two crystalline forms of 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine, C10H7Cl3N4 (code name BW1003C87) (I) and (II), have been carried out at liquid nitrogen temperature. A detailed comparison of the two structures is given. Both are centrosymmetric, with structure (I) in the triclinic space group P (1) over bar unit cell a = 6.4870(10), b = 9.216(2), c = 12.016(2) angstrom, alpha = 75.78(3)degrees, beta = 89.95(3)degrees, gamma = 83.45(3)degrees, V = 691.5(2) angstrom(3), Z = 2 and density (calculated) = 1.544 Mg/m(3); and (II) in the monoclinic space group P2(1)/c, unit cell a = 12.000(2), b = 7.518(2), c = 13.450(3) angstrom, beta = 97.87(3)degrees, V = 1202.0(5) angstrom(3), Z = 4, Density (calculated) = 1.600 Mg/m(3). Structure (I) includes a solvated CH3OH in the lattice. Final R indices [I > 2sigma(I)] are R1 = 0.0427, wR2 = 0.1075 for (I) and R1 = 0.0487, wR2 = 0.1222 for (II). R indices (all data) are R1 = 0.0470, wR2 = 0.1118 for (I) and R1 = 0.0623, wR2 = 0.1299 for (II). 5-Phenyl-2,4 diaminopyrimidine and 6-phenyl-1,2,4 triazine derivatives, which include lamotrigine (3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine), have been investigated for some time for their effects on the central nervous system. Both lamotrigine and 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine (code name BW1003C87), the subject of the present study, are anticonvulsant as well as neuroprotective in models of brain ischaemia and in a model of white matter ischaemia. BW1003C87 is a sodium channel blocker which also reduces the release of the neurotransmitter glutamate. The three dimensional structures reported here form part of a newly developed data base for the detailed investigation of members of this drug family and their biological activities.

Low temperature X-ray crystallographic structures of two lamotrigine analogues: (I) 2-methyl,3-amino, 5-imino-6-(2,3-dichlorophenyl)-1,2,4-triazine water solvate and (II) 2-methyl,3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine isethionate, hemi-hydrate

The X-ray crystal structures of two lamotrigine derivatives (I) 2-methyl, 3-amino, 5-imino-6-(2, 3-dichlorophenyl)-1,2,4-triazine, C10H9Cl2N5, as the hemi hydrate and (II) 2-methyl,3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine, C10H10Cl2N5, as the isethionate-water solvate, have been carried out at liquid nitrogen temperature. A detailed comparison of the two structures is given. Both are monoclinic and centrosymmetric, with (I) in space group C2/c, and (II) in space group P2(1)/n. For (I) the unit cell dimensions are a = 19.5466(10), b = 7.5483(4), c = 15.7861(8) angstrom, beta = 91.458(3)degrees, volume = 2328.4(2) angstrom(3), Z = 8, density = 1.590 Mg/m(3); for (II). For (II) the unit cell dimensions are a = 6.0566(2), b = 11.0084(4) c = 23.9973(9) angstrom, beta = 92.587(3)degrees, volume = 1598.35(10) angstrom(3), Z = 4, density = 1.597 Mg/m(3). For (I) final R indices [I > 2sigma(I)] are R1 = 0.0356, wR2 = 0.0782 and R indices (all data) are R1 = 0.0424, wR2 = 0.0817. For (II) final R indices [I > 2sigma(I)] are R1 = 0.0380, wR2 = 0.0871 and R indices (all data) R1 = 0.0558, wR2 = 0.0949. Both structures have a molecule of water of crystallization and (II) also includes a solvated CH3SO3. Comparisons are made between the two structures. Structure (I) is very unusual in having a = NH group at position C5' on the triazine ring. No other examples of this particular substitution, which is usually -NH2, have been reported.