2-(3-Chloro-5,6-diphenyl-2,5-dihydro-1,2,4-triazin-5-yl)-2-methyl-propane-nitrile.

The title compound, C(19)H(17)ClN(4), was obtained from the reaction of 3-chloro-5,6-diphenyl-1,2,4-triazine with isobutyronitrile in the presence of lithium diisopropyl-amide as an unexpected product of covalent addition of isobutyronitrile carbanion to the C-5 atom of the 1,2,4-triazine ring. The 2,5-dihydro-1,2,4-triazine ring is essentially planar (r.m.

5,5',6,6'-Tetra-methyl-3,3'-bi-1,2,4-tri-azine.

In the title compound, C(10)H(12)N(6), the two 5,6-dimethyl-1,2,4-triazine halves of the mol-ecule are related by a centre of symmetry. The two triazine rings are coplanar to within a maximum deviation of 0.013 (2) Å from the mean plane of the ring atoms.

Pyrazolo[4,3-e][1,2,4]triazines: purine analogues with electronic absorption in the visible region.

Synthesis of several pryrazolo[4,3-e][1,2,4]-triazines is described. The absorption spectrum of some 5-substituted derivatives was found to extend to the visible region. These compounds were found to inhibit some enzymes of purine metabolism, like xanthine oxidase or bacterial purine-nucleoside phosphorylase with Ki values in the 10(-3) -10(-5) M range.

Tandem vicarious nucleophilic substitution of hydrogen/intramolecular Diels-Alder reaction of 1,2,4-triazines into functionalized cycloalkenopyridines.

Synthesis of 2,3- and 3,4-cyclopentenopyridines, 5,6,7,8-tetrahydroquinolines and 5,6,7,8-tetrahydroisoquinolines from 1,2,4-triazine derivatives is reported. Introduction of an alpha-functionalized methyl substituent (e.g.

Synthesis of 5-imino-5H-dipyrido[1,2-a; 2',3'-d]pyrimidines as potential antiallergy agents (1).

A novel route to 5-imino-5H-dipyrido[1,2-a; 2',3'-d]pyrimidines is described. The method is based on the Ullmann condensation of 2-chloro-3-cyano-5-nitropyridine with 2-amino-pyridine 1-oxides, followed by intramolecular cyclization of the resulting 2-(3-cyano-5-nitro-2-pyridylamino)pyridine 1-oxides with phosphorous trichloride.

Synthesis of 5H-dipyrido[1,2-a:2',3'-d]pyrimidin-5-ones as potential antiallergy agents.

A novel synthesis of 5H-dipyrido[1,2-a:2',3'-d]pyrimidin-5-ones is described. The method is based on Ullmann condensation of 2-chloronicotinic acid and its 5-bromo analoguewith 2-aminopyridine 1-oxides, followed by intramolecular cyclization of the resulting 3-carboxy-2,2'-bipyridylamine 1'-oxides with phosphorous.

Antifungal properties of 1,2-dihydro-3-methylpyrido-(3,2-e)-as-triazine dihydrochloride (I-476).

Antifungal activity of compound I-476 (1,2-dihydro-3-methylpyrido[3,2-e]as-triazine dihydrochloride) was evaluated in vitro and in vivo. Minimal concentration inhibiting the growth of pathogenetic and saprophytic fungi in vitro ranged from 3.1 to 25 micrograms/ml.

Antifungal properties of a novel 1,2,4-triazine derivative I 319.

The antifungal activity of the sodium salts, of 3-thiolo-5-phenyl-1,2,4-triazine (I 319) was determined in vitro and in vivo. The minimal inhibitory concentration (MIC) of I 319 for 33 pathogenic and saprophytic fungal strains ranged from 3.1 to 25 microgram/ml.

Antitumor properties of selected 1,2,4-triazine derivatives.

Several new 3-thio-1,2,4-triazine derivatives were synthesized and investigated for antimicrobial and antitumor activity in in vitro and in vivo systems. Some of the investigated compounds inhibited growth of gram-positive bacteria and fungi at the concentration of 5-20 microgram/ml. Two methyl-nitro-imidazole-triazine derivatives (XI and XIII) inhibited the development of chicken fibroblast at 0.