The synthesis and characterization of eight new bis-cyclometalated compounds [M(ptpy)2(N^N)]PF6 (ptpy=2-(p-tolyl)pyridinato; N^N=5-chloro-1,10-phenanthroline: M=Rh, 1; M=Ir, 2); N^N=5-methyl-1,10-phenanthroline: 3; 4; N^N=4,4’-diphenyl-2,2’-bipyridine: 5; 6; N^N=4,4’-diamino-2,2’-bipyridine: 7; 8) are described. All were characterized by spectroscopic means. Additionally, the molecular structur...

2-Amino-5-nitro-6-ribitylamino-4(3H)-pyrimidinone (7) was phosphorylated with chlorophosphoric acid yielding an isomer mixture containing about 63% of the 5'-phosphate 7a together with other monophosphates and bisphosphates of 7. Preparative HPLC afforded pure 7a. Catalytic hydrogenation of 7a yields the labile substrate of pyrimidine deaminase, 2,5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5'-...

A human acute lymphoblastic T-cell line, MOLT-3, was fed with Roswell Park Memorial Institute Medium 1640-10% fetal bovine serum-antibiotics, containing increasing concentrations of methotrexate (MTX). After 10 months of feeding, the cells became resistant to 10(-7) M MTX; resistance was not reversed when the cells were placed in the original MTX-free medium. At 10(-7) M MTX, the concentration ...

Chelidamic acid (4-hy-droxy-pyridine-2,6-dicarb-oxy-lic acid) and 2,6-diamino-pyridine react to form the title salt, C(5)H(8)N(3) (+)·C(7)H(4)NO(5) (-); there are two formula units in the asymmetric unit. The pyridine N atom of 2,6-diamino-pyridine is protonated whereas chelidamic acid is deprotonated at both carboxyl-ate groups but protonated at the N atom; the reaction involves intra- and int...

1-alkyl aryl-5-amino-4-(cyanoformimidoyl)imidazoles 4 were reacted with malononitrile and 2-amino-1,1,3-propenetricarbonitrile under mild experimental conditions, which led to 5-amino-3-(substituted benzyl)-6,7-dicyano-3H-imidazo[4,5-b]pyridines 5 and 6,8-diamino-3-(4-substituted benzyl)-3H-imidazo[4,5-b]-1,8-naphthyridine-7,9-dicarbonitrile 6, respectively, when the reaction was carried out in...

This search involved synthesis of several new N-Substituted -3-chloro-
 2-azetidinones which were known as a high medicinal effectiveness for 2,
 4-Diamino-6-hydroxy pyrimidin in two steps. The first step included
 preparation Shiff bases (1-6) by condensation 2, 4-Diamino-6-hydroxy
 with many substituted aldehydes(4-hydroxy benzaldehyde, 2-
 bromobenzaldehyde, 4-dimeth...

In the title salt, C(5)H(8)N(3) (+)·C(7)H(3)N(2)O(7) (-), the pyridine N atom of the 3,4-diamino-pyridine mol-ecule is protonated. The 3,5-dinitro-salicylate anion shows whole-mol-ecule disorder over two orientations with a refined occupancy ratio of 0.875 (4): 0.125 (4). In the crystal, the cations and anions are connected by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds, forming a three-dime...

In the title compound, 4C(5)H(8)N(3) (+)·2C(8)H(4)O(4) (2-)·C(5)H(7)N(3), the asymmetric unit consists of two protonated diamino-pyridine cations, one phthalate anion and one half of a diamino-pyridine mol-ecule, which has twofold rotation symmetry and is disordered over two positions with a site-occupancy ratio of 0.534 (3):0.466 (3). In the disordered structure, both pyridine rings are essent...