Microwave Assisted Synthesis of 5-[4-(3-Phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenyl]-1H-tetrazole Derivatives and Their Antimicrobial Activity

Russian Journal of General Chemistry - In the present study, we report the synthesis of 5-[4-(3-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenyl]-1H-tetrazole derivatives by the Michael addition of...     

The parent of 2-(4,5-dihydro-1H-tetrazol-5-ylidene)-2-cyanoacetate: Synthesis and reactivity X-ray structure of (E)2-[1-(2,2-dimethylpropyl)-4,5-dihydro-1H-tetrazol-5-ylidene]-2-cyanoacetate

Reaction of 3,3-diazido-2-cyanoacrylate 5 with four moles of ammonia gives tetrazolyl-bisammonium salt 7 . The key-intermediate is the amino-vinyl azide 6 which spontaneously undergoes a 1,5′ ring-closure reaction followed by double deprotonation. Treatment of 7 with hydrochloric acid yields the parent of 2-(4,5-dihydro-1H-tetrazol-5-ylidene)-2-cyanoacetate 9 (R = Me, Et) as the only tautomer. Regiospecific monoalkylation of bisammonium salt 7a with dimethyl sulfate and reaction of ammonium salt 12 with hydrochloric acid gives (E)2-(1-methyl-4,5-dihydro-1H-tetrazol-5-ylidene)-2-cyanoacetate ( 13 ) (X-ray structure of derivative 14 ). Compound 13 can also be obtained from vinyl azide 10 and methylamine. This experiment as well as AM1 calculations of 9a, 23 and 24 strongly favour tautomer 9a .     

Synthesis and structure of mesomorphic 2-cyano-5-[p-alkyl(alkoxy)phenyl]-pyridines

Liquid-crystal 2-cyano-5-[p-alkyl(alkoxy)phenyl]pyridines were synthesized by the reaction of 1-dimethylamino-3-dimethylimmonia-2-[p-alkyl (alkoxy)phenyl]propene perchlorates with 2-acetylfuran and subsequently through 2-furyl-5-[p-alkyl(alkoxy)phenyl]pyrylium perchlorates and 2- (2-furyl)-5-[p-alkyl (alkoxy)phenyl]pyridines by conversion of the latter to 5-alkyl(alkoxy)phenylpyridine-2-carboxylic acids, from which the cyano derivatives were obtained by the usual scheme through the amides. The intermediate arylfurylpyridines and arylpyridine-2-carboxylic acid imides also display liquid-crystal properties.Translated from Khimiya Geterotskilicheskikh Soedinenii, No. 7, pp. 888–891, July, 1980.     

Oxidative ring-opening of rel-(2R,3R,5S)-5-aryl-2-benzoylamino-6,7-bis(methoxycarbonyl)-2,3-dihydro-1-oxo-3-phenyl-1H,5H-pyrazolo[1,2-a]-pyrazoles. Synthesis of rel-(2R,3R)-3-phenyl-3-[5-aryl-3,4-bis(methoxycarbonyl)pyrazolyl-1]alanine esters

rel-(2R,3R)-N-Benzoylamino-6,7-bis(methoxycarbonyl)-2,3-dihydro-1-oxo-1H,5H-pyrazolot[1,2-a]-pyrazoles 5 , accesible by cycloaddition of dimethyl acetylenedicarboxylate ( 3 ) to (1Z)-rel-(4R,5R)-1-aryl-methylidene-4-benzoylamino-5-phenyl-3-pyrazolidinone-1-azomethine imines 4 , undergo oxidative ring cleavage with methanolic bromine giving rel-(2R,3R)-N-benzoyl-3-phenyl-3-[5-aryl-3,4-bis(methoxy-carbonyl)pyrazolyl-1]alanine methyl esters 6 as products.     

Synthesis of 2-amino-4,4-bis(trifluoromethyl)-3-cyano-4,5-dihydro-1H-1,5-benzodiazepine

Conclusions The reaction of 1,2-phenylenediamine with 2,2-bis(trifluoromethyl)-1,1-dicyanoethylene leads to the formation of 2-amino-4,4-bis(trifluoromethyl)-3-cyano-4,5-dihydro-lH-l,5-benzodiazepine, whose structure was established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1920–1922, August, 1988.     

Synthesis of 1,3-dialkyl-5-(pyrrol-1-yl)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones

Russian Journal of Organic Chemistry -     

2-(2-Furyl)-5,6-dihydro-1(3)H-acenaphtho[4,5-d]imidazole. Synthesis and electrophilic substitution reactions

2-(2-Furyl)-5,6-dihydro-1(3)H-acenaphtho[4,5-d]imidazole was synthesized by the Weidenhagen reaction of acenaphthene-4,5-diamine with furfural. Alkylation of the title compound with methyl iodide in KOH-DMSO gave isomeric 1- and 3-methyl derivative, the latter being the major product. 2-(2-Furyl)-3-methyl-5,6-dihydro-3H-acenaphtho[4,5-d]imidazole was subjected to electrophilic substitution reactions (bromination, nitration, formylation, acylation, and sulfonation. Depending on the conditions, electrophilic attack was directed at the furan ring or acenaphthene fragment or both these.