5-phenyl-2H-tetrazol-2-ylmethyl ketones in the synthesis of tetrazolylalkanols and tetrazolyl(hydroxy)alkylphosphonates

The reduction of 1-(5-phenyl-2H-tetrazol-2-yl)propan-2-one and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanone with sodium tetrahydridoborate gave 1-(5-phenyl-2H-tetrazol-2-yl)propan-1-ol and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanol, respectively. Only 1-(5-phenyl-2H-tetrazol-2-yl)propan-2-one was reduced with baker’s yeast with an appreciable yield. 1-(5-Phenyl-2H-tetrazol-2-yl)propan-2-one and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanone reacted with diethyl phosphonate in the presence of potassium fluoride to produce the corresponding diethyl [hydroxy(5-phenyl-2H-tetrazol-2-yl)alkyl]phosphonates.     

Tetrazole compounds. 9. A new approach to tetrazolyl-substituted quinoline derivatives

The acid-catalyzed reaction of 1-aryl-5-(2-dimethylaminovinyl)-1H-tetrazoles 2 with arylamines suitably functionalized in the ortho-position resulted in Z-configurated transamination products which were cyclized to novel 3-tetrazolylquinolines by the action of sodium ethoxide. Thus, on reacting 2 with 2-aminoacetophenone or 2-aminobenzophenone, respectively, the 2-[2-(1-aryl-1H-tetrazol-5-yl)vinyl-amino]aryl ketones 3a-g were obtained, the cyclization of which gave 4-substituted 3-(1-aryl-1H-tetrazol-5-yl)quinolines 4 . In the case of the transamination products 3h-1 , prepared from 2 and methyl anthranilate, the ring closure afforded 3-(1-aryl-1H-tetrazol-5-yl)-1H-quinolin-4-ones 5 . Starting from 2 and anthranilonitrile 4-amino-3-(1-aryl-1H-tetrazol-5-yl)quinolines 10 were obtained via the corresponding intermediates 9 .     

Tetrazoles: XLIX. Alkylation of tetrazoles with tetrakis(chloroacetoxymethyl)methane

Alkylation of 1-aryl-4,5-dihydro-1H-tetrazol-5-ones and 1-phenyl-4,5-dihydro-1H-tetrazole-5-thione with tetrakis(2-chloroacetoxymethyl)methane in boiling acetonitrile in the presence of potassium bromide and triethylamine gives tetrakis[2-(4-aryl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)acetoxymethyl]-methanes and tetrakis[2-(1-phenyl-1H-tetrazol-5-ylsulfanyl)acetoxymethyl]methane, respectively. The alkylation process is considerably accelerated under microwave irradiation.     

Tetrazole compounds. 10. Novel tetrazolylindoles by fischer indolization of substituted tetrazolylacetaldehyde phenylhydrazones

The acid-catalyzed reaction of substituted phenylhydrazines 1 with 1-aryl-5-(2-dimethylaminovinyl)-1H-tetrazoles 2 afforded (1-aryl-1H-tetrazol-5-yl)acetaldehyde phenylhydrazones 3 which on heating in acetic acid/perchloric acid underwent a Fischer indolization to give substituted 3-(1-aryl-1H-tetrazol-5-yl)-indoles 4a-k. Indoles of this type are also formed on subjecting 1 and 2 directly to indolization conditions; thus, starting from phenylhydrazine the tetrazolylindoles 41-s were obtained by a one-pot procedure. Indolization of corresponding N_α-methylphenylhydrazones 5 resulted in 1-methyl-3-(1-aryl-1H-tetrazol-5-yl)indoles 6 .     

Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones. I. 3-unsubstituted compounds

Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones via a Pechmann condensation of 3-carbethoxy-1-methyl-4-piperidone with various phenols is described. The limitations of this method are discussed. Synthesis of the parent ring system 3a via reduction of 1,2,3,4-tetrahydro-3-(phenylmethyl)-8-[(1-phenyl-1H-tetrazol-5-yl)oxy]-5H-[1]benzopyrano[3,4-c]pyridin-5-one ( 5 ) is also described.     

Synthesis of 1-phenyi-1H-tetrazolo[4,5-d]tetrazole and 5-aryl-1-(4-bromophenyl)-1,2,4-triazolo[4,3-d]tetrazoles

l-Phenyl-lH-tetrazol-5-yIhydrazine (2) was reacted with nitrous acid to yield 1-phenyl-lH-tetrazolo[4,5-d]tetrazole (3). l-Arylidene-2-(l-phenyl-lH-tetrazol-5-yl)hydrazines (4) were generally reactive towards electrophilic reagents. When treated with bromine in acetic acid, 4 yielded mixtures of 1-arylidene-2-[1-(4-bromophenyl)-lH-tetrazol-5-yl]hydrazines (5a-d) and 2-[1-(4-bromophenyl)-lH-tetrazol-5-yl]hydrazidic bromides (6a-d). Solvolysis of 6a-d in aqueous acetone yielded 5-aryl-1-(4-bromophenyl)-1,2,4-triazolo[4,3-d]tetrazoles (7a-d). The structures of the synthesized compounds were confirmed on the basis of elemental analysis, IR and ¹H NMR data.     

Synthesis of [5-(1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl)-1,3,4-oxadiazol-2-yl]pyridines

2-, 3-, and 4-[5-(1-Aryl-5-R-1H-1,2,3-triazol-4-yl)-1,3,4-oxadiazol-2-yl]pyridines were synthesized from the corresponding 1-aryl-5-R-1H-1,2,3-triazole-4-carbonyl chlorides and 2-, 3-, and 4-(1H-tetrazol-5-yl)-pyridines.     

Reactions of 2-isocyanatobenzoyl chloride and 2-carbomethoxyphenyl isocyanate with 5-aminotetrazole

Treatment of 2-isocyanatobenzoyl chloride ( 4 ) with 5-aminotetrazole (5-AT) gave 3-(5-tetrazolyl)quinazoline-2,4(1H,3H)-dione ( 1 ) directly. Treatment of 2-carbomethoxyphenyl isocyanate ( 5 ) with 5-AT gave 2-[((5-amino-1H-tetrazol-1-yl)carbonyl)amino]benzoic acid methyl ester ( 6 ) as a kinetic product, which was thermally isomerized to 2-[((1H-tetrazol-5-ylamino)carbonyl)amino]benzoic acid methyl ester ( 7 ), the thermodynamically more stable urea. Cyclization of 7 with polyphosphoric acid gave 2-(1H-tetrazol-5-ylamino)-4H-3,1-benzoxazin-4-one ( 2 ). Urea 6 was quite labile in solution, as shown by nmr, and readily reacted with methanol to give 2-[(methoxycarbonyl)amino]benzoic acid methyl ester ( 10 ).     

Julia–Kocienski approach to trifluoromethyl-substituted alkenes

A Julia–Kocienski approach to trifluoromethyl-substituted alkenes was evaluated in the reactions of 1,3-benzothiazol-2-yl, 1-phenyl-1H-tetrazol-5-yl, and 1-tbutyl-1H-tetrazol-5-yl 2,2,2-trifluoroethyl sulfones with aldehydes. Among the various conditions tested, the best yields were obtained with 1-phenyl-1H-tetrazol-5-yl 2,2,2-trifluoroethyl sulfone, in CsF-mediated, room temperature olefinations in DMSO. Aromatic aldehydes gave (trifluoromethyl)vinyl derivatives in 23–86% yields, with generally moderate stereoselectivity. Straightforward synthesis of the Julia–Kocienski reagent, and conversion to trifluoromethyl-substituted alkenes under mild reaction conditions, are the advantages of this approach.     

2-(1-苯基-1H-四唑-5-硫基)-N-芳基乙酰胺的合成及其生物活性研究

采用微波法通过2-氯乙酰芳胺与1-苯基-1H-四唑-5-硫醇反应合成了一系列2-(1-苯基-1H-四唑-5-硫基)-N-芳基乙酰胺. 其结构经 IR, ¹H NMR, ¹³C NMR 和元素分析表征. 生物活性实验结果表明, 该类化合物在较低浓度下对油菜籽和小麦的生长表现出良好的促进作用.     

Heterocyclic system. XI. Synthesis of 1H,4H-pyrazolo[4,3-b]pyrrolizine and 2H,4H-pyrazolo[4,3-b]pyrrolizine derivatives

Cyclization of pyrrolidinocarboxamide derivatives of 1-phenyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylic acid and 2-phenyl-3-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylic acid afforded imminium salts which were transformed into the corresponding ketones. Further reduction of the latter compounds furnished the title derivatives.     

The synthesis of 3H-pyrazol-3-one derivatives containing a 9H-xanthene ring

2,4-Dihydro-5-methyl-2-phenyl-4-(9H-xanthen-9-yl)-3H-pyrazol-3-one ( 3 ) was prepared by the condensation of phenylhydrazine and ethyl α-acetyl-9H-xanthene-9-acetate ( 2 ), or 9H-xanthen-9-ol ( 1 ) and 2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one ( 4 ). 5-Amino-2,4-dihydro-2-phenyl-4-(9H-xanthen-9-yl)-3H-pyrazol-3-one ( 6 ) was obtained by the condensation of 1 and 5-amino-2,4-dihydro-2-phenyl-3H-pyrazol-3-one ( 5 ).     

Synthesis and biological evaluation of 5-methyl-4-phenyl thiazole derivatives as anticancer agents

Abstract

New N-(5-methyl-4-phenylthiazol-2-yl)-2-(substituted thio)acetamides were synthesized and studied for their anticancer activity. The title compounds were procured by reacting 2-chloro-N-(5-methyl-4-phenylthiazol-2-yl)acetamide with some mercapto derivatives. The structural elucidation of the compounds was performed by ¹H-NMR, ¹³C-NMR and LC-MS/MS spectral data and elemental analyses. The synthesized compounds were investigated for their antitumor activities against A549 human lung adenocarcinoma cells and NIH/3T3 mouse embryoblast cell line for determining their selective cytotoxicity. 2-[(1-methyl-1H-tetrazol-5-yl)thio]-N-(5-methyl-4-phenylthiazol-2-yl)acetamide (4c) showed high selectivity, and whose IC₅₀ value was determined as 23.30?±?0.35?µM and >1000?µM against A549 human lung adenocarcinoma cells and NIH/3T3 mouse embryoblast cell lines, respectively. 2-[(1-Methyl-1H-imidazol-2-yl)thio]-N-(5-methyl-4-phenyl thiazol-2-yl)acetamide (4a) and 2-[(1-Methyl-1H-tetrazol-5-yl)thio]-N-(5-methyl-4-phenyl thiazol-2-yl)acetamide (4c) exhibited the highest apoptosis percentage among those tested, but not as high as the standard, cisplatin.     

Synthesis of 3H-pyrazol-3-one derivatives containing a 9H-thioxanthene ring

2,4-Dihydro-5-methyl-2-phenyl-4-(9H-thioxanthen-9-yl)-3H-pyrazol-3-one ( 3 ) was prepared by condensing 9H-thioxanthen-9-ol ( 1 ) with 2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one ( 2 ), or by cyclizing ethyl α-acetyl-9H-thioxanthene-9-acetate ( 4 ) with phenylhydrazine. 2,4-Dihydro-5-methyl-2-phenyl-4-(9H-thioxan- then-9-yl)-3H-pyrazol-3-one 10,10-dioxide ( 8 ) was prepared by cyclizing ethyl α-acetyl-9H-thioxanthene-9-acetate 10,10-dioxide ( 7 ) with phenylhydrazine. Compound 8 was also obtained by oxidizing 3 with hydrogen peroxide in acetic acid. 5-Amino-2,4-dihydro-2-phenyl-4(9H-thioxanthen-9-yl)-3H-pyrazol-3-one ( 10 ) was obtained by condensing 1 with 5-amino-2,4-dihydro-2-phenyl-3H-pyrazol-3-one ( 9 ).     

Exploring the unique reactivities of heterobicyclic tetrazoles—access to functionally diverse and versatile heterocyclic scaffolds

The benzylic hydrogen atom in oxabicyclic tetrazoles such as (6R,8R)-(8-phenyl-5,6-dihydro-8H-tetrazolo[5,1-c][1,4]oxazin-6-yl)-alkanols (A, X=CH₂OH) is highly acidic, being alkylated in preference to a hydroxymethyl group with NaH and active alkyl halides. The enantioenriched products B now contain a phenyl and alkyl group on a stereogenic benzylic carbon atom. The products are subject to β-elimination to give 1-{1-[3-propenyl]-1H-tetrazol-5-yl}-1-phenyl-alkanols. Cleavage of the propenyl chain leads to chiral non-racemic 1-phenyl-1-(1H-tetrazol-5-yl)-alkanols C. Free-radical ‘anomeric’ azidation of the oxabicyclic tetrazoles followed by reduction and ring closure with inversion of configuration produces azabicyclic tetrazoles D as constrained functionalized piperazines.     

O-(1-Phenyl-1H-tetrazol-5-yl) Glycosides: Alternative synthesis and transformation into glycosyl fluorides

A number of new glycosyl donors, O-(1-phenyl-1H-tetrazol-5-yl) glycosides, are prepared from the corresponding hemiacetals, commercially available 5-chloro-1-phenyl-1H-tetrazole ( 2 ), and tetrabutylammonium fluoride (Bu₄NF) in either THF or DMF. The mild reaction conditions are compatible with a variety of protecting groups. The glycosyl donors are treated with hydrogen fluoride-pyridine complex (HF·py) to rapidly provide glycosyl fluorides in good-to-excellent yields, apparently by a (single or double) S_N2 mechanism as studied by both ¹H- and ¹⁹F-NMR spectroscopy. Under acidic conditions, glycosyl fluorides equilibrate partially or completely, equilibration requiring a large excess of HF · py.     

Development of a new synthesis of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone,sodium salt via an amidine intermediate

A new synthesis of the recently reported 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone, sodium salt ( 1 , MDL-427), an experimental mediator release inhibitor, was developed from: (1) reaction of 5-aminotetrazole 3 and triethyl orthoformate 6 to give ethyl N-(1H-tetrazol-5-yl)formimidate 8 , (2) reaction of methyl anthranilate and imidate 8 to give amidine 11 , and (3) treatment of 11 with base to give 1 . Investigation of each of these steps independently led to a significantly more efficient, facile and higher-yielding 1-pot process. A brief examination of anthranilic acid 13 and its salts and derivatives 14 to 17 in this process found them to have dissimilar reactivities. The formation of amidine 11 as an isolable intermediate was unusual, as was its failure to cyclize under standard neutral or acidic conditions. The absolute requirement for base to effect cyclization of 11 appears to be unprecedented.     

Synthesis and selected transformations of 1-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)ethanones and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl]ethanones

By cycloaddition of arylazides to acetylacetone are obtained derivatives of 1,2,3-triazole. In the reaction of 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] ethanones (VIIa-VIIe) with isatin are obtained 2-[1-(R-phenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-4-quinolinecarboxylic acids (IIIa–IIIe) and 2-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] -4-quinolinecarboxylic acids (IXa, IXb), respectively. We found that 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) readily transform into [5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] acetic acids (IVa–IVc) by the method of Wilgerodt-Kindler. The (5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)acetic acid reacts with 5-phenyl-4-amino-4H-1,2,4-triazol-3-thiol affording 6-[(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl) methyl]-3-phenyl[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazole (VI). Original Russian Text ? N.T. Pokhodylo, R.D. Savka, V.S. Matiichuk, N.D. Obushak, 2009, published in Zhurnal Obshchei Khimii, 2009, vol. 79, no. 2, pp. 320–325.     

Synthesis of 1-(5-phenyl-2H-tetrazol-2-ylacetyl)-4-substituted thiosemicarbazides as possible antiinflammatory agents

A series of 1-(5-phenyl-2H-tetrazol-2-ylacetyl)-4-substituted thiosemicarbazids were prepared as possible antiinflammatory agents. Their antiproteolytic activity was reported.     

Synthesis and Reactions of 5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7 H -thiazolo[3,2- a ]pyrimidine-6-carbonitrile

5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7H-thiazolo[3,2-a]pyrimidine-6-carbonitrile was synthesized via the reaction of 4-(2-aminothiazol-4-yl)-3-methyl-1-phenyl-2-pyrazolin-5-one with benzylidene malononitrile and was then transformed to related fused heterocyclic systems. The antifungal and antibacterial studies revealed in some cases excellent biocidal properties.