Photochemical reactions of group VIB metal carbonyls with heterocyclic Schiff bases derived from 4-amino -3-hydrazino-5-mercapto-1,2,4-triazole

The new complexes, M(CO)₅(Schiff base) [M?=?Cr; 1, Mo; 2, W; 3, Schiff base?=?4-salicylidenamino-3-hydrazino-5-mercapto-1,2,4-triazole, SAHMT, a; 4-(2-hydroxynaphthylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole, 2HNAHMT, b; 4-(3-hydroxybenzylidenamino)-3-hydrazino-5-mercapto-1,2,4- triazole, 3HBAHMT, c; 4-(4-hydroxybenzylidenamino)-3-hydrazino-5-mercapto-1,2,4- triazole, 4HBAHMT, d; 4-(5-bromosalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole, 5BrSAHMT, e; were synthesized by photochemical reaction of metal carbonyls M(CO)₆ (M?=?Cr, Mo, W) with new heterocyclic Schiff bases derived from 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, a–e. The ligands and complexes have been characterized by elemental analysis, EI-mass spectrometry, FT-IR, ¹H and ¹³C-{¹H}-NMR spectroscopy. The spectroscopic studies show that Schiff bases, a–e, are monodentate and coordinate via azomethine N donor to the central metal atom in M(CO)₅(Schiff base) (M?=?Cr, Mo, W).     

Synthesis,Characterization and X‐ray Structures of AMTT‐Type Schiff bases and two CuI Complexes (AMTT= 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione)

The reaction of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT) with 4‐methylbenzaldehyde and 4‐methoxybenzaldehyde in ethanol led to the iminic derivatives ‐4‐(4‐methylbenzylideneamino)‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)thione ( L1 ) and 4‐(4‐methoxybenzyl‐ideneamino)‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione ( L2 ). The reaction of L1 with CuCl in the presence of triphenylphosphane as co‐ligand in methanol/chloroform solution gave the Cu^I complex containing L1 , [Cu( L1 )(PPh₃)₂Cl]·0.5CH₃OH·0.25CHCl₃ ( 1 ). Treatment of L2 with the same metal salt in a molar ratio of 1:1 in methanol and further addition of a solution of PPh₃ in chloroform led to the complex [Cu( L2 )(PPh₃)₂Cl]·2.5CHCl₃ ( 2 ). The complexes and L1 were characterized by IR and NMR spectroscopy as well as by X‐ray diffraction studies. In both complexes, the Schiff base ligand is coordinated to the copper ion through its sulfur atom. The other coordination sites around the copper ion are occupied by two triphenylphosphane molecules and one chloride ion. Therefore, each Cu^I ion is in a distorted tetrahedral environment. Crystal data for L1 at ?100 °C: space group P2₁/n with a = 720.5(1), b = 1140.6(1), c = 1426.3(2) pm, β = 91.25(1)°, Z = 4, R₁ = 0.03, for 1 at ?120 °C : space group with a = 1286.3(1), b = 1740.3(1), c = 2060.2(1) pm, α = 79.085(6), β = 83.827(5), γ = 76.688(6)°, Z = 4, R₁ = 0.0649 and for 2 at ?80 °C : space group with a = 1183.7(2), b = 1370.1(2), c = 1812.1(3) pm, α = 85.69(2), β = 88.52(2), γ = 64.89(2)°, Z = 2, R₁ = 0.0488.     

Synthesis,Characterization, and Crystal Structure of the New Schiff‐Bases derived from 1,2,4‐Triazole and the Structure of [(PPh3)2Cu(AMTT)]NO3·EtOH (AMTT = 4‐Amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione)

The reactions of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT, L1 ) with 2‐thiophen carbaldehyde, salicylaldehyde and 2‐nitrobenzaldehyde in methanol led to the corresponding Schiff‐bases ( L1a‐c ). The reaction of L1 with [(PPh₃)₂Cu]NO₃ in ethanol gave the ionic complex [(PPh₃)₂Cu(L1)]NO₃·EtOH ( 2 ) All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for L1a at 20 °C: space group P2₁/n with a = 439.6(2), b = 2074.0(9), c = 1112.8(4) pm, β = 93.51(3)°, Z = 4, R₁ = 0.0406, L1b at ?80 °C: space group P2₁/n with a = 1268.9(2), b = 739.3(1), c = 1272.5(1) pm, β = 117.97(1)°, Z = 4, R₁ = 0.0361, L1c at ?80 °C: space group P2₁/n with a = 847.8(1), b = 1502.9(2), c = 981.5(2) pm, β = 110.34(1)°, Z = 4, R₁ = 0.0376 and for 2 at ?80 °C: space group with a = 1247.8(1), b = 1270.3(1), c = 1387.5(1) pm, α = 84.32(1)°, β = 84.71(1)°, γ = 63.12(1)°, Z = 2, R₁ = 0.0539.     

N-多氟烷基取代和葡萄糖基取代的1,2,4-三唑-5-硫酮类席夫碱的合成及其杀虫活性

为改善三唑类化合物的生物活性, 以3-苯基-4-氨基-1,2,4-三唑-5-硫酮为原料, 将其与芳香醛在冰醋酸体系中反应, 得到3-苯基-4-芳基亚甲氨基-1,2,4-三唑-5-硫酮类席夫碱(4a～4i). 在此基础上, 化合物4a～4i分别与多氟烷基碘代烷和溴代乙酰基葡萄糖反应合成了一系列1,2,4-三唑-5-硫酮类席夫碱的多氟烷基取代物5a～5r和葡萄糖基取代物6a～6d, 并用¹H NMR, ¹⁹F NMR, IR和MS谱以及元素分析表征了它们的结构. 初步生物活性测试结果表明, 部分目标化合物具有明显的杀虫活性.     

Synthesis,Characterization and Crystal Structures of 1,2,4‐Triazole based Schiff‐Bases and their Copper(I) Complexes

The reaction of of 4‐amino‐5‐ethyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AETT, L ) with furfural in methanol led to the corresponding Schiff‐Base ( L1 ). The reaction of L1 with [Cu(PPh₃)₂]Cl in methanol gave to the neutral compound [( L1 )Cu(PPh₃)₂Cl] ( 1 ). By recrystallization of 1 from CH₃CN the complex [( L1 )Cu(PPh₃)₂Cl]·CH₃CN ( 1a ) was obtained. All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for L1 at ?80 °C: space group with a = 788.4(1), b = 830.3(2), c = 928.8(2) pm, α = 84.53(1)°, β = 65.93(1)°, γ = 72.02(1)°, Z = 2, R₁ = 0.0323; for 1 at ?100 °C: space group with a = 1166.3(1), b = 1423.8(2), c = 1489.1(2) pm, α = 62.15(1)°, β = 72.04(1)°, γ = 88.82(1)°, Z = 2, R₁ = 0.0338 and for 1a at ?100 °C: space group P2₁/c with a = 1294.1(1), b = 1019.8(2), c = 3316.9(4) pm, β = 94.73(1)°, Z = 4, R₁ = 0.0435.     

Synthesis and pancreatic lipase inhibitory activities of some 1,2,4-triazol-5(3)-one derivatives

In this study, starting from 4-amino-5-(4-chlorobenzyl)-2,4-dihydro-3H-1,2,4-triazole-3-one ( 1 ), the 4-Amino-5-(4-chlorobenzyl)-2-undecyl-2,4-dihydro-3H-1,2,4-triazol-3-one ( 2 ) was first synthesized and this compound was converted to Schiff base derivatives ( 3a-e ). In the second step of the study, the 2-[3-(4-chlorobenzyl)-5-oxo-1-undecyl-1,5-dihydro-4H-1,2,4-triazole-4-yl]-acetohydrazide ( 6 ), which was used as a key product in the synthesis of many heterocyclic compounds was synthesized in four steps, and then this compound was converted into methylidene acetohydrazide ( 7a-e ), thiosemicarbazide ( 8a-e ), and 1,2,4-triazole-5-thione ( 9a-e ) derivatives. Also, in the last part of the study, 1,2,4-triazole-5-thione derivatives were changed into Mannich bases ( 10a-b ) bearing a 4-phenylpiperazine ring. These new compounds were tested with regard to pancreatic lipase (PL) inhibition activity, and compound 3b , 3d , 7d , 8d , and 9d showed a considerable anti-lipase activity at various concentrations. The activity of compounds 7b (IC₅₀ = 1.45 ± 0.12 μM) was the highest in terms of IC₅₀, comparable to that of orlistat, a well-known PL inhibitor used as an antiobesity drug.     

Synthesis,Characterization and Molecular Structure of a New Tetrameric Palladium(II) Complex Containing Schiff‐Bases Derived from AMTTO (AMTTO = 4‐amino‐6‐methyl‐1,2,4‐triazine‐thione‐5‐one)

The reactions of AMTTO = 4‐amino‐6‐methyl‐1,2,4‐triazine‐thione‐5‐one (AMTTO, 1 ) with 2‐hydroxybenzaldehyde (salicylaldehyde) and 4‐hydroxybenzaldehyde in methanol under reflux conditions led to the corresponding Schiff‐bases ( H₂L1 and H₂L2 ). The reaction of H₂L1 with palladium acetate in ethanol and additional recrystallization from toluene gave the tetrameric complex [Pd(L)]₄·2C₇H₈ ( 2 ). All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for H₂L1 at ?80 °C: space group P2₁/c with a = 1285.4(1), b = 707.7(1), c = 1348.2(1) pm, β = 109.32(1)°, Z = 4, R₁ = 0.0328, H₂L2 at ?80 °C: space group P4₃2₁2 with a = 762.5(1), b = 762.5(1), c = 4038.9(2) pm, Z = 8, R₁ = 0.025 and for 2 at ?103 °C: space group C2/c with a = 2862.5(6), b = 2847.6(6), c = 1727.8(4) pm, β = 105.18(3)°, Z = 8, R₁ = 0.0704.     

A linear trinuclear cobalt(II) complex with 4-(2-pyridine)-1,2,4-triazole: synthesis,structure and characterization

The linear trinuclear cobalt(II) complex [Co₃(pytrz)₆(H₂O)₆](NO₃)₆ (1) with pytrz = 4-(2-pyridine)-1,2,4-triazole has been prepared and characterized. It crystallizes in the rhombohedral R-3 space group with Z = 3, a = 13.955(2), b = 13.955(2), c = 28.942(9) Å, γ = 120°, V = 4881.2(18) ų. The structure of 1 comprises the cation [Co₃(pytrz)₆(H₂O)₆]⁶⁺, in which linear trinuclear Co(II) units are bridged by six L ligands and have six aqua molecules as terminal ligands. The six free nitrates link the terminal aqua ligands through N–H ··· O hydrogen bonds with C₃ symmetry. 1 was characterized by FT-IR, electronic spectra and magnetic measurements. The variable-temperature magnetic measurements reveal weak anti-ferromagnetic interactions in 1.     

3-(N-取代苯基-2-乙酰胺基)硫基-4-N-取代邻羟苯基亚胺基-5-甲基-1,2,4-三唑类化合物的合成及生物活性研究

以对称二氨基硫脲为原料,与冰醋酸反应生成5-甲基-4-氨基-1,2,4-三唑-3-硫酮(1);在弱酸性条件下,1与取代水杨醛反应生成席夫碱中间体5-甲基-4-(N-取代邻羟苯基)亚胺基-1,2,4-三唑-3-硫酮(2a～2c);最后在碱性条件下分别与N-取代苯基-2-氯乙酰胺发生烷基化反应生成15种未见报道的目标化合物3-(N-取代苯基-2-乙酰胺基)硫基-4-(N-取代邻羟苯基)亚胺基-5-甲基-1,2,4-三唑(3a～3o),其结构经IR,1H NMR,13C NMR确证.初步生物测试表明,质量分数为0.01%时,3a～3o对白色念珠菌的抑菌率均达90%以上,具有很强的抑菌活性;对金黄色葡萄球菌、大肠杆菌的抑菌率达80%以上,具有较强的抑菌活性.     

Synthesis and In Vitro Anti-HIV Activity of Some New Schiff Base Ligands Derived from 5-Amino-4-phenyl-4H-1,2,4-triazole-3-thiol and Their Metal Complexes

New Schiff base ligands (6–9) derived from 5-amino-4-phenyl-4H-1,2,4-triazole-3-thiol 1 and substituted benzaldehydes (2–5) as well as their metal complexes with Cu(II), Fe(II), Au(III), and Mn(II) (12–17) have been synthesized. A new benzothiazole derivative (11) was prepared from coupling of 7 with N-(benzothiazol-2-yl)-2-chloroacetamide 10. Their spectral properties were investigated. The newly designed and synthesized Schiff base ligands and the metal complexes were assayed for anti-HIV-1 and HIV-2 activity by examination of their inhibition of HIV-induced cytopathogenicity in MT-4 cells. Compounds 11 and 16 were found to be the most active inhibitors in cell culture (EC₅₀ = 12.2 μg/mL (SI = 4) and > 2.11 μg/mL (SI = > 1), respectively) against HIV-1, whereas 11 showed inhibition against HIV-2 of EC₅₀ > 10.2 μg/mL with SI = 9, which provided a good lead for further optimization.     

5-(4,6-Diphenyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione with Some C-Electrophiles and N-Nucleophiles

5-(4,6-Diphenyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione reacted with haloalkanes or their derivatives containing side chain oxo group to give S-alkylated compounds. Aminomethylation and acylation of the thione yielded N₍₃₎-derivatives. Treatment of the title compound with hydrazine hydrate in butanol resulted in 4-amino-5-(4,6-diphenyl-2-pyrimidinyl)-1,2,4-triazole-3-thione via a recyclization reaction. Reaction of the title compound with hydrazine hydrate or phenylhydrazine in dioxane led to formation of the corresponding thiocarbohydrazides. The latter in the presence of a base were cyclized to 4-amino-1,2,4-triazole-3-thiones.     

Facile synthesis of [1,2,4]triazino[4,3-b][1,2,4,5]tetrazepin derivatives by a one-pot reactions using 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5 (4H)-one

<正>4-Amino-3-mercapto-6-methyl-l,2,4-triazin-5(4H)-one 1 converted to 4-amino-6-methy-3-(methylthio)-1,2,4-triazin-5(4H)-one by methylation with methyl iodide.Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6- methyl-l,2,4-triazin-5(4H)-one 2 as a building block,to the synthesis of some novel derivatives of[1,2,4]triazino- [4,3,b][1,2,4,5]tetrazepine 3-6,by the reaction with 3-chloropentane-2,4-dione,chloro acetonitrile,1,3-dichloroacetone,and methyl bromoacetate.This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1,2- bielectrophiles derivatives.     

Synthesis and structures of iron(iii) complexes based on azo derivatives of 5-oxo- and 5-thioxopyrazole

New potentially tridentate ligands, viz., 3-methyl-1-phenyl-4-(quinolin-8-ylhydrazono)pyrazol-5(1H)-one and 3-methyl-1-phenyl-4-(quinolin-8-ylhydrazono)pyrazole-5(1H)-thione (LH), and their complexes with Fe^III were synthesized. The structures of the ligands and metal chelates (FeL₂A; A = ClO₄ or FeCl₄) were studied by ¹H NMR spectroscopy and magnetochemistry. The FeL₂A complex (A = FeCl₄) was investigated by X-ray diffraction. These low-spin complexes have pseudooctahedral structures with the N₄X₂ ligand environment (X = O or S).     

The synthesis of 5H-thiazolo[2,3-c][1,2,4]triazine derivatives and substituted 3-(2-acylvinylthio)-1,2,4-triazin-5-ones from 6-methyl-3-thioxo-1,2,4-triazin-5-one, 1-acyl-2-bromoacetylenes,and α-acetylenic ketones. X-ray study of 3-benzoyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazin-5-one

3-Acyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazines were synthesized by reaction of 1-acyl-2-bromoacetylenes with 6-methyl-3-thioxo-1,2,4-triazin-5-one in methanol in the presence of triethylamine at 20 °C. The structure of 3-benzoyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazine was established by X-ray structural analysis. Substituted 3-(2-acetylvinylthio)1,2,4-triazin-5-ones were obtained by the reaction of -acetylenic ketones with 6-methyl-3-thioxo-1,2,4-triazin-5-one under the same conditions. The structures of the new compounds were confirmed by IR,¹H, and¹³C NMR spectroscopy.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2971–2975, December, 1996.     

Condensed Imidazo-1,2,4-azines. 31. Synthesis and Chemical Transformations of Substituted 1,2,4-Triazepino[2,3-a]benzimidazoles

By reaction of 1,2-diaminobenzimidazole with 1,3-diketones, acetoacetic ester and its derivatives, we have synthesized substituted 1,2,4-triazepino[2,3-a]benzimidazole and 5H-1,2,4-triazepino[2,3-a]benzimidazol-4-one. By reaction of 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazol-4-one with aromatic aldehydes or phenyldiazonium chloride, we have obtained 3-arylidene(phenylazo) derivatives of this compound, and by reaction with P₂S₅ we have obtained 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazole-4-thione. We have shown that when reacted with ammonia, primary or secondary amines, the latter forms 4-amino-substituted 2-methyl-1,2,4-triazepino[2,3-a]benzimidazole.     

Regioselectivity of cyclization of 1-(6-methyl-5-oxo-2,5-dihydro-1,2,4-triazin-3-yl)-4-arylthiosemicarbazides by treating with methyl iodide and dicyclohexylcarbodiimide

1-(6-Methyl-5-oxo-2,5-dihydro-1,2,4-triazin-3-yl)-4-arylthiosemicarbazides treated with methyl iodide in the presence of sodium acetate in ethanol convert into 6-methyl-3-arylamino[1,2,4]-triazolo[4,3-b][1,2,4]triazin-7(1H)-ones. In reaction with dicyclohexylcarbodiimide 6-methyl-3-arylamino[1,2,4]triazolo[3,4-c][1,2,4]triazin-5(1H)-ones were obtained which at heating in alcohol solution in the presence of sodium acetate or at 262–272°C underwent the Dimroth rearrangement to give 3-methyl-7-arylamino[1,2,4]triazolo[5,1-c][1,2,4]-triazin-4(8H)-ones.     

The Reactions of 6-(tert-Butyl)-3-hydrazino-1,2,4-triazin-5(2H)-one with Carbonyl Compounds

The reaction of 6-(tert-butyl)-3-hydrazino-1,2,4-triazin-5(2H)-one with acetone and benzaldehyde yields the corresponding hydrazones. In the presence of thionyl chloride the benzaldehyde hydrazone is converted to 3-(tert-butyl)-6-phenyl-1,2,4-triazolo[4,3-b]-1,2,4-triazin-2(1H)-one and this can also be formed via the acylation of the starting hydrazinotriazinone using benzoyl chloride.     

Synthesis, characterization, and antitumor activity of azomethine derivative of triazole and its complexes with copper(I) and zinc(II) salts

4-[(2-Hydroxy-5-bromobenzylidene)amino]-3-methyl-1,2,4-triazole-5-thione, a new azomethine derivative of triazole, was synthesized. This Schiff base reacts with the copper(I) and zinc(II) salts in a 2:1 molar ratio to afford complexes. The resulting compounds were characterized by the 1H NMR, IR, UV spectroscopy and by elemental analysis.     

Synthesis of certain 6-alkylthio-2,2′-anhydro-5-azauridines

β-D-Arabinofurano[1′,2′:4,5]oxazolo-s-triazin-4-one-6-thione ( 7b ) and its t-butyldimethylsilyl protected counterpart 7a were synthesized by treating the appropriate 2-amino-β-D-arabinofurano[1′,2′:4,5]-2-oxazoline with ethoxycarbonyl isothiocyanate. These 2,2′-anhydro-s-triazine nucleosides were then subjected to alkylation under similar reaction conditions. Alkylation of 3′,5′-bis(O-t-butyldimethylsilyl)-β-D-arabinofurano[1′,2′:-4,5]oxazolo-s-triazin-4-one-6-thione ( 7a ) provided the targeted S-alkylated nucleosides, i.e., the C6-SCH₃ ( 9a ), C6-SCH₂-CH = CH₂ ( 10a ), and C6-S-CH₂-C = CH ( 11a ), in reasonable yields. Attempted deprotection of these nucleosides failed. In order to circumvent this problem, 7b was alkylated with the same reagents. In each case, instead of the expected S-alkylated anhydronucleosides, a mixture of the 5-N-alkylanhydro-s-triazine-4,6-dione and 5-N-alkylanhydro-s-triazin-4-one-6-thione derivatives were obtained. The 2,2′-anhydro linkage of 7a was also found to be more stable than the s-triazine ring to mild base. Basic conditions displaced the C6-sulfur substituent and eventually caused ring opening of the s-triazine aglycone.     

Synthesis and Antimicrobial Activities of Some 6-Methyl-3-Thioxo-2,3-Dihydro-1,2,4-Triazine Derivatives

Abstract

4-Arylidene-imidazole derivatives (4a,b) were readily prepared by reacting 4-am- ino-6-methyl-3–thioxo-2,3–dihydro[1,2,4]triazin-5(4H)-one (1) with 4-arylidene-2-phenyl- 4H-oxazol-5-one (2). Reaction of 1 with some aromatic aldehydes in presence of triethylphosphite exclusively afforded the corresponding aminophosphonates 5a-c. Reaction of 1 with 3-phenyl-1H-quinazoline-2,4-dione (6a) and/or 3-phenyl-2-thioxo-2,3-dihydro- 1H-quinazolin-4-one (6b) gave 2-(6-methyl-5-oxo-3-thioxo-2,5-dihydro-3H-[1,2,4]triazin-4-ylimino)-3-phenyl-2,3-dihydro-1H-quinazolin-4-one (7). Moreover, on treating 1 with 2-phenylbenzo[d][1,3]thiazine-4-thione (8), 6-methyl-4-(2-phenyl-4-thioxo-4H-quinazolin-3-yl)-3-thioxo-3,4-dihydro-2H-[1,2,4]triazine-5-one (9) was obtained in 65% yield. Reaction of 1 with 4-sulfonylaminoacetic acid derivatives (10a,b) afforded the corresponding sulfonamides (11a,b), respectively. Acid hydrolysis of 11a afforded 7-aminomethyl-3-methyl[1,3,4]thiadiazole[2,3-c][1,2,4]triazin-4-one (12). 4-Amino-6-methyl-3-(morpholine-4-ylsulfanyl)-4H-[1,2,4]triazin-5-one (14) was prepared by reacting compound 1 with morpholine in presence of KI/I₂, while 3,3′-bis(4-amino-6-methyl-5-oxo-triazinyl)disulfide (16) was obtained by oxidation of 1 with lead tetraacetate. The antimicrobial activity of the products was evaluated against Gram-positive and Gram-negative bacteria as well as the fungus Candida albicans.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures, and tables.]