Synthèse,réduction chimique et électrochimique de benzopyranno[1][4,3-e] et [3,4-e]pyrimido[1,2-b]-as-triazinones

From 9H-amino [l]benzopyranno-as-triazines 2 and 3 , [l]ben-zopyranno[4,3-e] or [3,4-e]pyrimido[l,2-b]-as-triazinones have been prepared by reaction with β-ketoesters. Chemical reduction of the compounds gives tetrahydro derivatives. By electrochemical reduction the dihydro compounds 14 and 15 were from-ed. The same dihydro derivatives were obtained with Grignard reagents.     

Quelques réactions nuclé ophiles et électrophiles de la thiéno[2,3-b]pyrazine. Comparaison de sa réactivite avec celles de thiéno diazines et de la thiényl-2 pyrazine dans le cas de la nitration

We studied the action of nbutyllithium, the action of chlorine and the action of nitric acid in sulfuric acid medium on thieno-[2,3-b]pyrazine, These reactions led us to comparethe behaviour of thieno[2,3-b]pryazine with that of thieno[2,3-d]pyrimidine and of thieny1-2pyrazine under the same consitions.     

Spectrométrie de Masse D'hétérocycles Séléniés. III—Etude de la Fragmentation de Quelques Selenolo [2, 3-b] Pyridines

The mass spectra of thirteen selenolo[2,3-b]pyridine derivatives have been measured and compared with those of benzo[b]selenophene, quinoline and thieno[2,3-c]pyridine. The influence of diheteroatomic structure of the nucleus on the mechanism of fragmentation of the oxygenated substituents is discussed.     

Synthèse d'analogues bihétérocycliques du phénanthrène: Les méthyl-1-[1]benzothinéo,benzoséléno[2,3-b ]pyrroles,et méthyl-1-[1]benzofuro,benzothiéno et benzoséléno[3,2-b ]pyrroles

The condensation of ethyl sarcosinate on 2- or 3-halogeno 3- or 2-formyl[1]benzofuran. benzothiophene or benzoselenophene, and on the related 2h-[1]-3-benzoheteroyclanones is described. In the last instances the resulting compounds were formylated in teh 2-position with subsequent. After hydrolysis and decarboxylation, the I1methy][1]benzothieno-, benzoseleno [2,3-b]pyrroles were were thus obtained.     

Propriétés de la benzopyranno[1][2,3-b]quinoxalinone-12

Under basic conditions. [1]benzopyrano[2,3-b]quioxakin-12-one leads to 3-(i-hydroxybenzoy1)-1H-quinoxalin-2-one. This ketone reacts with hydroxylamine and phenylhydrazine to give the expected derivatives or those of [1]benzopyrano92,3-b]quinoxalin-12-one. The reduction of [1]benzopyrano[2,3-b]quinoxalin-12-one was unsucessful by chemical means. However, electrochemical reduction leads to a dihydropyrazine nucleus.     

Facile synthesis of novel indolo[3,2-b]carbazole derivatives and a chromogenic-sensing 5,12-dihydroindolo[3,2-b]carbazole

Novel indolo[3,2-b]carbazole derivatives and a chromogenic-sensing 5,12-dihydroindolo[3,2-b]carbazole have been synthesized starting from tetra-tert-butylated 6,12-diaryl-5,11-dihydroindolo[3,2-b]carbazoles, which were prepared via an efficient tert-butylation of 6,12-diaryl-5,11-dihydroindolo[3,2-b]carbazoles.     

Dérivés de l'imidazo[2,l-b]thiazole. IX. Comportement du phénacyl-3 dihydro-5,6 imidazo[2,1-b]thiazole et du phénacylidène-3 tétrahydro-2,3,5,6 imidazo[2,1-b]thiazole vis-à-vis du chlorhydrate d'hydroxylamine

The reaction of hydoxylamine hydrochloride with two imidazothiazoles, having a ketonic carbonnyl group, leads to two types of compounds according to the quantity of the sodium acetate used. 3-Phenacyl-5,6-dihydroimidazo[2,1-b]thiazole hydrochloride gives logically the corresponding oxime, isolated in salt form or as a base depending upon the quantity of sodium acetate added. Furbase depending upon the quantity of sodium acetate added. Furthermore, a systematic allylic rearrangement was observed with migration of thiazole double bond to the adjacent nuclear position. 3-Phenacylidene-2,3,5,6-tetrahydroimidazo[2,1-b]thiazole gave directly in the absence of sodium acetate, a rearranged oxime salt. On the other hand, in the presence of sodium acetate, we obtained a hgydroxylamine which was characterized by a double bond in the 2,3-position of the thiazole ring. It is noteworthy that no transformation of the hydroxylamine into the oxime or vice-versa occurs whatever the pH of the solution. These different compounds have no fungistatic activity in contrast to the corresponding ketones.     

Systèmes aromatiques à 10 électrons π dérivés de l'aza-3a pentalène. IX—etude par RMN de l'équilibre azide/tetrazole dans le cas du tetrazolo [5,1-b] benzothiazole

Azido-tetrazole equilibrium is observed in the case of a solution of tetrazolo [5,1-b] benzothiazole in CDCl₃, using proton magnetic resonance at 250 MHz. Analysis of the spectra obtained yields the chemical shifts and the coupling constants of the two tautomeric forms.     

Ionic Liquid-Mediated Facile Synthesis and Antimicrobial Study of Thiazolo [2,3-b]Benzo[h]Quinazolines and Thiazino[2,3-b] Benzo-[h]Quinazolines

Abstract

8-Methoxy-4-phenyl-3,4,5,6-tetrahydrobenzo[h]quinazoline-2(1H)-thione, obtained by the condensation of 2-benzylidene-6-methoxy-3,4-dihydronapthalene-1(2H)-one with thiourea, on reaction with chloroacetic acid and 3-chloropropanoic acid in the presence of the ionic liquid N-methylpyridinium tosylate furnishes 3-methoxy-7-phenyl-7,10-dihydro-5H- benzo[h]thiazolo[2,3-b]quinazoline-9(6H)-one and 3-methoxy-7-phenyl-5,6,10,11-tetrahydro- benzo[h][1,3]thiazino[2,3-b]quinazoline-9(7H)-one. Further, condensation of the thione with 1,2-dibromoethane and 1,3-dibromopropane yields 3-methoxy-7-phenyl-6,7,9,10-tetrahydro-5 H-benzo[h]thiazolo[2,3-b]quinazoline and 3-methoxy-7-phenyl-5,6,7,9,10,11-hexahydrobenzo [h][1,3]thiazino[2,3-b]quinazoline respectively. Arylidene derivatives have been obtained by two routes. The structures of the cyclized compounds have been established on the basis of elemental analysis and spectroscopic data. The synthesized compounds were screened for antimicrobial activity. Some of the compounds showed promising antimicrobial activities.     

Etude des conditions d'accés aux 6H-, 7H- et 11H-pyrimidino-[4,5-a], [4,5-b], [5,4-a] [5,4-b] et [5,4-c]carbazoles. 1

The synthesis of dihydropyrimidinocarbazoles 12,15 and 18 was achieved by cyclization of tetrahydrocarbazolones with triformamidomethane. The oxidation with potassium permanaganate of dihydropyrimidinocarbazoles gave the pyrimidinocarbazoles 13,16 and 19. The application of the Sandemeyer reaction to amiononitrocarbazoles gave cyanonitrocarbazoles which could be reduced to aminocyanocarbazoles 1 and 7. Intramolecular cyclization of the carbazoles 1 and 7 afforded 3,4-dilhydro-4-oxo-6H-pyrimidino[5,4-b]carbazole 2 and 1,2-dighydro-1-oxo-6H-pyrimidino[5,4-b]carbazole 10 was obtained by cyclization of quinazolinyl hydrazone 9 with hydrochloric acid and acetic acid. The structure of the derivatives was determined by ¹H-nmr and the Overhauser effect.     

New derivatives of imidazo [5, 1-b] benzothiazole

1-Cyano-3-phenylimidazo[5, 1-b]benzothiazole (II) has been obtained from 1-formyl -3-phenylimidazo[5, 1-b]benzothiazole (I) and from 1-brono-3-phenylimidazo[5, 1-b]benzothiazole (III) and has been converted into the corresponding amide (IV) and thioamide (V). New 1-alkyl-3-phenylimidazo[5, 1-b]benzothiazoles (VI) have been synthesized.     

s-Triazolo[4,3-b]pyridazines and imidazo[4,5-c]pyridazines

8-Amino-s-triazolo[4, 3-b]pyridazine (I), an adenine analog has been prepared by two different routes. Likewise 8-amino-3-phenyl-s-triazolo[4,3-b]pyridazine (V) has been prepared. Both of these compounds have been prepared utilizing 3,4,5-trichloropyridazine and 3,4,6-trichloropyridazine as the starting materials thus interrelating the 3,4,5-and the 3,4,6-series. A variety of other transformations have been carried out.     

Reactivity of sym-triazolo[3,4-b ]benzothiazole

The reactivity of sym-triazolo[3,4-b]benzothiazole (I) has been studied. Compound I is stable under the conditions of acid hydrolysis; when it is heated with acetic anhydride in the presence of sodium acetate or with an aqueous solution of alkali, the triazole ring opens with the formation of 2-acetylamino- and 2-aminobenzothiazoles, respectively. Compound I has been brominated in position 3 and has been subjected to the Vilsmeier and Mannich reactions. The thiosemicarbazone and oxime of sym-triazolo[3,4-b]benzothiazole-3-carbaldehyde have been obtained, and the oxime has been converted into the corresponding nitrile. The thioamide, ester, and hydrazide of sym-triazolo[3,4-b]benzothiazole-3-carboxylic acid have also been obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 916–919, July, 1970.     

Spectres photoélectroniques de divers thiéno[2,3-b] thiophènes

Photoelectron spectra of thieno[2,3-b]thiophene and its mono halogeno and mono methyl derivatives have been analysed. The proposed assignments were confirmed by the effects of di, Iri and tetra substitutions and are in good agreement with a CNDO/S calculation.     

Synthèse et étude conformationnelle de dioxa-1,3 aza-9 spiro[5,5]undecanes

Synthesis of the new l,3-dioxa-9-azaspiro[5.5]undecane ring, was realized by the scheme represented in Figure 2. Butyro-phenones 6 posses neuroleptic activity similar to that of halo-peridol. The pharmacological activity was reported in another publication (2). Conformational study of l,3-dioxa-9-azaspiro-[5.5]undecanes shows the existence of four conformations A, B, C and D, which are shown in Figure 4. The existence of these conformations depends on the nature of the substituents R and R' on the dioxane ring. Thus, in the compounds where R ≠ H, R' = H, the four conformations are possible with a preponderance of A and B. If R and R' are different from H only the conformation A is present in 99% concentration. Lastly, when R = R' = H, the four conformations are possible with equal population for the couple A, B and the couple C, D; the first couple predominating. The presence of a fluorophenylbutyric moiety on the piperidine nitrogen does not seem to stereochemically modify the heterocyclic group.     

Investigation of nitrogen- and sulfur-containing heterocycles. 44. New heterocyclic systems. Derivatives of imidazolidino-[3,2-f]pyrido[2,3-b]-and imidazolidino[3,2-f]pyrimido[4,5-b]-1,4-thiazines. Synthesis and structure

New representatives of heterocyclic systems, imidazolidino[3,2-f]-pyrido-[2,3-b]- and imidazolidino[3,2-f]pyrimido[4,5-b]-1,4-thiazines, have been obtained. Intermediate compounds of 5N-oxalamides-6-hydroxy-7H-pyrido[2,3-b]-1,4-thiazine have been isolated and characterized. Amides of N-(pyridyl-3)- and N-(pyrimidyl-5)-oxaminic acids have been obtained.For communication 43, see [1].Translated from Khimiya Geterotsiklicheskikh Soedininii, No. 7, pp. 992–997, July, 1986.     

Synthèses d'hétérocycles indoliques à partir de dérivés carbonylés de l'indole et du pyrrole

The reactions of ethyl azidoacetate with 1-methylindole-2-3-dicarboxaldehyde (1) and its monoacetal 2 afforded β and γ carbolines. The regioselectivity of condensation of ethy6l aminoacetate with 1 was investigated and yields a γ-carboline. Derivatives of a new heterocycle, the thiepino[4,5-b]indole and its application of the synthesis of some carbazoles are described.     

Green synthetic approach toward new chromeno[4,3-b]quinoline and chromeno[4,3-b]pyridine derivatives

Chemistry of Heterocyclic Compounds - A facile, convenient, and efficient synthesis of new chromeno[4,3-b]quinoline and chromeno[4,3-b]pyridine derivatives has been accomplished via one-pot...     

Nouvelles voies d'accès à des aryl-4 thiéno[2,3-c]pyridines et à des aryl-7 thiéno[3,2-c]pyridines

4-Arylthieno[2,3-c]pyridines and 7-arylthieno[3,2-c]pyridines have been prepared by heating in polyphosphoric acid 2-(2-thenylamino>l-arylethanols or propanols and 2- 3-thenylamino>l-arylethanols or propanols, respectively.) Under the Beckmann rearrangement conditions, oximes of 4-aryl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one lead to 4-aryl-4,5- dihydro-6H-thieno[2,3-c]pyridin-7-one.     

Synthesis of substituted imidazo[5,1-b]benzimidazoles

Some chemical characteristics and reactions of 3-phenyl-4-methylimidazo[5,1-b]benzimidazole (I) have been examined. It has been shown that I undergoes electrophilic substitution (hydroxymethylation, acetylation, nitrosation, and the Mannich and Vilsmeier reactions), the substituent entering at the 1-position. Cyanoethylation of I gives 1-cyanoethyl-3-phenyl-4-methylimidazo[5,1-b]benzimidazole.For part III, see [3].