v-triazolines. Part XIV . 1-aryl-5-dialkylaminomethyl-4-methylene-4,5-dihydro-v-triazoles

The cycloaddition of arylazides to 1-methyl- and 1-benzyl-2,5-dihydropyrrole affords pyrrolo[3,4-d]-v-triazole derivatives which react with methyl iodide, yielding the corresponding quaternary ammonium salts. On base-catalyzed elimination 1-aryl-5-dialkyl-aminomethyl-4-methylene-4,5-dihydro-v-triazoles are formed. Their structure and behaviour toward methoxide and secondary amines are discussed.     

Synthesis of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b][1,4]-diazepin-6-ones from 4,5-diamino-1H-pyrimidin-6-ones and 1-aryl-3-(dimethylamino)-1-propanones

The reaction of 1-aryl-3-(dimethylamino)-1-propanones 1 with one equivalent of 4,5-diamino-1H-pyrimidin-6-ones 2 , in acidic medium, leads to the formation of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b]-[1,4]diazepin-6-ones 3 . The structure elucidation of the products is based on detail nmr analysis of experiments such as ¹³C, ¹H and DEPT including selective ¹³C{¹H} decoupling experiments.     

Rearrangement of 2-amino-1-aryl-1,4-dihydropyridines

Heating of 2-amino-1-aryl-1,4-dihydropyridines in acidic aqueous media gives 2-arylamino-1,4-dihydropyridines. The reaction formally involves the migration of the aryl substituent from the endo-to exocyclic N atom. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1260, July, 2006.     

v-triazolines. Part XVI. Synthesis of benzothiepino[4,5-d]-v-triazole derivatives

The cycloaddition reaction of some arylazides to enamines 4a-f afforded v-triazolines 5a-i ; by subsequent acid-catalyzed hydrolysis v-triazoles 6a-c were obtained. The reversibility of the cycloaddition was demonstrated on the basis of spectroscopic or chemical evidences.     

Amidrazones 11. Rearrangement of 1-allyl-substituted-4,5-dihydro-1-methyl-1H-pyrazolium bromides

1-Methyl-2-(2-propenyl)-3-pyrazolidinimine ( 5 ) was obtained by treatment of 3-amino-4,5-dihydro-1-methyl- 1-(2-propenyl)-1H-pyrazolium bromide ( 4 ) with ethanolic sodium ethoxide. Similar treatment of the analogous 2-(2-butenyl) and 2-(3-phenyl-2-propenyl)-substituted salts 12 and 15 gave 1-methyl-2-(1-methyl-2-propenyl)-3- pyrazolidinimine ( 13 ) and 1-methyl-2-(1-phenyl-1-propenyl)-3-pyrazolidinimine ( 16 ) respectively.     

Reactions of 4,5-diamino-3-methyl-1-phenylpyrazole with diarylideneacetones

The reaction of 4,5-diamino-3-methyl-1-phenylpyrazole with dibenzylideneacetone and its 4,4-derivatives has been studied; the reactions lead to aromatic 1H-2,3-dihydropyrazolo[5,4-b]1,5-diazepine derivatives. The reaction pathway has also been identified.Translated from Khimiya Geterotsiklicheskikh Sodinenii, No. 11, pp. 1563–1567, November, 1987.     

Reactions of 4,5-diamino-3-methyl-1-phenylpyrazole with aromatic haloketones

Reaction of 4,5-diamino-3-methyl-1-phenylpyrazole with -bromoacetophenones yields pyrazolo[4,5-b]pyrazines. A side product is 1-phenyl-3-methyl-5-imino-4-[(1-phenyl-3-methyl-4-aminopyrazol-5-yl)imino]-2-pyrazoline obtained by dimerization of the starting diaminopyrazole with loss of ammonia and a molecule of hydrogen.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 787–790, June, 1988.     

2-Imidazolines. III (1). 1-Aryl- and 1-acyl-2-amino-(ormethoxy)-4,5-diamino-4,5-dihydroimidazoles. Synthesis and properties

Diimmonium salt (5) reacts with guanidines (6) and o-methylisoureas (7) affording 2-amino-4,5-dimorpholinoimidazolines (9) . 1-Aryl-2-amino-4,5-dimorpholinoimidazolines lose the amino functionality under mild acidic conditions with formation of 2-amino-5-morpholinoimidazole derivatives (10) whereas 1-acyl derivatives undergo under the same conditions a ring expansion process leading to pyrimidine derivatives (13) .     

A modified scheme for the synthesis of 1-benzyl-4,5-diamino-1,2,3-triazole

Conclusions A modified scheme was proposed for the synthesis of 1-benzyl-4, 5-diamino-1,2,3-triazole involving the use of high pressure (5–6 kbar) which permits a significant increase in the yield of this product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2633–2634, November, 1985.     

Preparation of 1-aryl-2-methyl-3-carbethoxy-4,5-dioxo-6-bromoindoles

1-Aryl-2-methyl-3-carbethoxy-5-hydroxy-6-bromoindoles are oxidized by nitric acid to 1-aryl-2-methyl-3-carbethoxy-4,5-dioxo-6-bromoindoles, while 1,2-dimethyl-3-carbethoxy-5-hydroxy-6-bromoindole is converted to the 4,6-dinitro derivative under similar conditions.     

5-Amino-4,5-dihydroisoxazoles. Part I. 5-Amino-3-aryl-4-methylene-4,5-dihydroisoxazoles and 4-aminomethyl-3-arylisoxazoles from 5-amino-4-aminomethyl-3-aryl-4,5-dihydroisoxazoles

5-Amino-4-aminomethyl-3-aryl-4,5-dihydroisoxazoles 2 were obtained by cycloaddition of nitrile oxides to 1,3-diaminopropenes 1. On reaction with methyl iodide the corresponding 4-(quaternary)-ammoniomethyl iodides 3 were formed. These compounds, on reaction with bases, afforded 5-amino-3-aryl-4-methylene-4,5-dihydroisoxazoles 4. The acid-catalyzed deamination of compounds 2 afforded 4-aminomethyl-3-arylisoxa-zoles 5 and 3-arylisoxazoles as retro-Mannich products. The deamination of 2 to yield 5 was also obtained by base catalysis.     

Five-membered 2,3-dioxo heterocycles: C. Reaction of methyl 1-aryl-3-cinnamoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carbocylates with acyclic enamines

Methyl 1-aryl-3-cinnamoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carbocylates react with N-substituted ethyl 3-amino-3-phenylprop-2-enoates, ethyl 3-aminobut-2-enoates, 3-amino-1,3-diphenylprop-2-en-1-ones, and dimethyl 2-arylaminofumarates to give 9-ethoxycarbonyl-, 9-benzoyl-, and 8,9-bis(methoxycarbonyl)-4-cinnamoyl-1,7-diazaspiro[4.4]nona-3,8-dienes.