A general synthesis of as‐triazines and bis‐as‐triazines

Abstract

The most important syntheses of as-triazines have received some amount of systematic study; these include semicarbazide, thiosemicarbazide or aminoguanidine reactions with 1,2-dicarbonyl compounds or their monoximes, with a-keto acids or their esters or amides, or with a-hydroxy ketones (1). The parent compound, 1,2,4-triazine, has only recently been prepared for the first time (2).Recent publications by Case (3,4) report amidrazones (hydrazidines) of the formula RC-(=NH) NHNH2 undergo cyclocondensation readily with diketones such as benzil and pyridil to form 3,5,6-trisubstituted 1,2,4-triazines (astriazines) of formula I.We have recently been concerned with t h e study of various heteroaromatic systems, and now wish to report that amidrazones of the aforesaid formula and bis-amidrazonesof the formula R'[C-(=NH)NHNH2 l2 will also undergo cyclocondensation readily with glyoxal (Ar-COCHO) and bis-glyoxalyl [Ar'(COCH0)2 J compounds t o form I II 111 I V COCHO 8 -2H20 COCHO Vlll V, X -H VI. X . NOp VI1.X O H I X . X = H X . X -NO2

Comparative analysis of self-aggregation of liquid crystalline Pt(II) complexes in solution and in neat films

“…4-MMethoxyphenyl glyoxal was used as a starting material therefore the last step was demethylation in molten pyridinium chloride. Alternatively, the phenol 2 can be prepared from known triazine 7 [10]. Indeed, despite the electron rich nature of 4-hydroxyphenyl substituent, the triazine 7 can still be used in inverse electron demand Diels-Alder reaction with 1-morpholinocyclopentene and gave phenol 2 in good yield.…”

Structure of 5,5',6,6'-tetraphenyl-3,3'-bi-1,2,4-triazine

“…(Ernst & Kaim, 1986 Tazuke, 1989). 3,Y-Bi-l,2,4-triazines are readily accessible in high yields by cyclocondensation of a,/3-diketones with oxamidodihydrazone (Case, 1965;Culbertson & Parr, 1967;Dedichen, 1936;Jensen & Pflaum, 1965;Kiss, 1984) and various substituents R can be easily introduced to the bi-triazine frame:…”

3-Aryl-as-triazines as potential antiinflammatory agents

“…5-Phenyl-3-(2-pyridyl)-os-triazine (4a). An ethanol solution of 2-pyridylamidrazone (1.36 g, 0.01 mol) and phenylglyoxal (1.52 g, 0.01 mol) was refluxed for 2 h. The cooled solution was diluted with water and the resultant precipitate filtered: 1.5 g (64%); mp 142.5-145 °C (lit.7 140-141 °C); NMR 9.92 (s, 1), 8.83 (d, 1, J = 5 Hz), 8.52 (m, 3), 7.96 (m, 1), 7.53 (aromatic H's). Anal.…”

“…C, , N, Cl. Ethyl 3-(p-Chlorophenyl)-5,6-dihydro-5-oxo-as-triazine-6-carboxylate ( 7). This procedure is described by Taylor and Notes Martin.28 An ethanolic solution of diethyl 2-ketomalonate (1.75 g, 0.01 mol) and p-chlorobenzamidrazone (1.7 g, 0.01 mol) was stirred at room temperature for 18 h. The filtered reaction was evaporated and the residue crystallized from 2-propanol to give 0.9 g (32%): mp 247-250 °C (lit.28 mp 244 °C); NMR (Me2SO-d6-CDCl3) & 8.17 (d, 2,J=10 Hz), 7.52 (d, 2, J = 10 Hz), 4.45 (q, 2, =7 = 8 Hz), 1.40 (t, 3, J = 8 Hz).…”

“…o-Fluorophenylamidrazone (3h) was prepared by a two-step sequence from o-fluorobenzamide via initial activation with methyl fluorosulfonate and subsequent The reaction of p-chlorobenzamidrazone (3a) with diethyl oxalate and 2-ketomalonate gave 5-carbethoxy-2-(p-chlorophenyl)triazole (6) and 6-carbethoxy-3-(pchlorophenyl)-5(4H)-os-triazone (7), respectively (Scheme III).…”