Recherches en série diazépine-1,4 et triazépine-1,2,4. IX. Synthéses de nouvelles triazépines-1,2,4

The methods used to prepare five types of 1,2,4-triazepines disubstituted by oxo, thioxo, methoxy or methylthio groups in the 3 and 5 positions are described. Thus eleven triazepines have been synthesized and their structure established from the spectral data.     

Recherches en série diazépine-1,4 et triazépine-1,2,4. XV. Syntlièse d'halogéno-3(7)-s-triazolo[4,3-b] triazépinones

Halogenation of s-triazolo[4,3-b]triazepinones gas been accomplished by several methods. According to the agents used it has been possible to halogenate the triazepine ring (C-7 carbon) or (and) the triazole ring (C-3 carbon). Thus eighteen halogeno triazolotriazepines have been synthesized and their structures established from the spectral data.     

Recherches en série diazépine-1,4 et triazépine-1,2,4. X. Réductions et méthylations de pyrazolo[3,4-b]diazépines-1,4

Reduction and methylation of pyrazolo[ 3,4-b ]diazepines have been effected by several methods. According to the reducing agents used, it has been possible to reduce selectively the C?N double bond, the carbonyl group, to reduce the diazepinone rings completely and to reduce partially or completely the insaturated parts of the (6H)pyrazolodiazepines. Methylation on the amide nitrogen, on oxygen of the same function, and in a few cases on the C₆ carbon of the pyrazolodiazepinones and finally on the 4 position in tetrahydropyrazolodiazepinones have been obtained.     

Recherches en série triazépine-1,2,4: II — Etude de la réaction de l'acétylacétate d'éthyle avec les diamino-3,4 oxo-5 dihydro-4,5 triazines-1,2,4

The reaction of 3,4-diamino-5-oxo-4,5-dihydro-l,2,4-triazine or its 6-methyl or 6-phenyl substituted derivatives and ethyl acetoacetate gave three compounds: 4,7-dioxo-9-methyl-1,4,6,7-tetrahydro-as-triazino[4,3-b]-1,2,4-triazepine in poor yield, isomeric 4,9-dioxo-7-methyl-1,4,8,9-tetrahydro-as -triazino[4,3-b]-1,2,4-triazepine and by competitive cyclisation, 2-methyl-7-oxo-3,7-dihydro-s-triazolo[3,2-c]-1,2,4-triazine. By condensation of 3-methylamino-4-amino-5-oxo-4,5-dihydro-1,2,4-triazine with ethyl acetoacetate, the formation of 4,9-dioxo-7,10-dimethyl-4,8,9,10-tetrahydro-as-triazino[4,3-b]-1,2,4-triazepine was strongly favored.     

Régio et périsélectivité de réactions de diels-alder et des cycloadditions dipolaires-1,3 avec une triazépine-1,2,4: Approche théorique

e.s The cycloaddition of 1,3-dipoles (mesitonitrile, C,N-dimethylnitrone) and various dienophiles (DMAD, maleic anhydride) to 1,2,4-triazepine 1 are peri and regiospecific. Nitrone excepted the preferred orientation of addition is predicted correctly by FMO/MNDO calculation.     

Nouvelles synthèses de systèmes bicycliques hétéroaromatiques. I. Cycloaddition [4 + 2]π de la diméthyl-2,7 diméthylthio-3,5 triazépine-1,2,4

The cycloaddition of 3,5-dimethylthio-1,2,4-triazepine (1) to various dienophiles has been studied. 4-Phenyl-1,2,4-triazoline-3,5-dione, dimethyl acetylene dicarboxylate and meleic anhydride react with I to give the [4+2]π cycloadduct. The heterocyclic products were found to be formed via 1,3-sigmatropic rearrangement of this cycloadduct.     

Synthèse spécifique de pyrimidines. Formation conccurentielle de pyrimidines et de triazépines

Nucleophilic displacement of ethyl cyanoacetic ester on compounds 1 or 2 with hydrazines yielded only pyrimidines 3, 4 or 11 . Triethyl orthoformate (or triethyl orthoacetate) reacting with o-aminohydrazides produced a mixture of pyrimidines 3 or 11 and the triazepine 10 .     

Recherches en série triazepine-1,2,4: 1 - détermination de la structure de la triazolotriazépinone obtenue par action de l'acétylacétate d'éthyle sur le diamino-3,4 triazole-1,2,4

The condensation of 3,4-diamino 1,2,4-triazole with ethyl aceloacelate gave 6-methyl-8,9-dihydro(7H)-s-triazolo[4,3-b]-1,2,4-triazepin-8-one ( 2 ); 2 has been caracterized by nmr spectroscopy and by comparison with its methylated derivative prepared in an unambigous manner.     

Synthèse de nouvelles amidines bicycliques . Dérivés de la pyrimidine,de la quinazoline et de la diazépine-1,3

The synthesis of pyrrolo[1,2-α] pyrimidines is described. Several homologous compounds contain pyridine or azepine instead of pyrrole ring. They are obtained by cyclization of iminolactams with β-ketoesters, αβ-unsaturated esters, aldehydes or ketones, or diketene. The possibility of obtaining isomers is discussed.     

Mise en evidence de la chiralité de l'édifice spirophosphoranique

The chirality of the spirophosphorance skeleton of the recemic mixture 2a , 2ā , is revealed by the NMR chiral shift reagent.     

Nouveaux types de sucres triazotés: triazènes et phénylimino-2-oxadiazoles-1,3,4. Communication préliminaire

Novel types of sugars bearing three nitrogen atoms: triazenes and 2-phenylimino-1, 3, 4-oxadiazoles . A series of aminodeoxysugars treated with p-nitrobenzenediazonium tetrafluoroborate led to the corresponding triazenes, each of which in chloroform solution existing as an equilibrium between its two tautomeric forms. The free energy of activation of the exchange of the proton between the two nitrogen atoms has been estimated by variable temperature ¹H-NMR. measurements. Each triazenylsugar gave on acetylation an unique positional isomer bearing its acyl group on the nitrogen atom directly attached to the glycosyl group. Phenylsemicarbazones of two keto-sugars were oxidized with El Khadem's reagent (I₂, HgO, MgO) to give the corresponding spiro-2-phenylimino-1, 3, 4-oxadiazoles.     

Transposition de neber en série tétrahydropyrannone

The Neber rearrangement applied to the oxime tosylates of the 4- and 3-tetrahydropyranones gives the α-aminoacetals 5 and 20 , as well as 3-amino-4,4-diethoxy and 2-amino-3,3-diethoxy-tetrahydropyranes. The hydrolysis of the former gives the pyrazine 6 and the latter gives the aminoketone 21. On the other hand the aminoacetal 5 allows one to obtain the 4-acetoxy-3-trimethylammonium tetrahydropyran iodide ( 12 ) with a preferential cis axial acetoxy equatorial trimethylammonium conformation. The oxime tosylate of the 3-tetrahydropyranone readily undergoes the Beckman rearrangement into lactam 18 whose open chain product is the (3-aminopropoxy)acetic acid ( 19 ).     

Fragmentation en Spectrométrie de Masse D'Imidazobenzodiazépines

The mass spectra of a series of imidazo[4,5,1-jk]1,4-benzodiazepines and imidazo[1,5,4-ef]1,5-benzodiazepines have been examined. The differences in the fragmentation patterns permit the isomeric structures to be identified.     

Etude de l'oxydation de tétrahydroisoquinoléinols-4 diméthoxylés en 6,7 ou 7,8, et sur la réactivité du carbonyle de la tétrahydroisoquinolone-4 diméthoxylée en 6,7

Preparation of the tetrahydroisoquinolin-4-ols indicated in the title and their oxidation by different reagents (chromic anhydride, NBA, dimethylsulfoxide, Oppenauer oxidation) is reported. Only the last reaction led to the title compounds, while the other reagents (except NBA) yielded 1,2,3-trioxotetrahydroisoquinoline. Furthermore, the reactivity of 6,7-dimethoxytetrahydroisoquinolin-4-one was examined towards different carbonyl reagents.     

Isomérisation de 2,3‐époxypinanes fonctionnels en présence d'acides de Lewis

Isomerization of Functionalized 2,3‐Epoxypinanes in the Presence of Lewis Acids The functionalized 2,3‐epoxypinanes 1b – i were submitted to isomerization in the presence of ZnBr₂ at 110° (Table 1) or of BF₃⋅Et₂O at different temperatures (Table 2), and their behavior was compared with that of the non‐functionalized parent 1a and with similar known transpositions. The produced campholenals 2 , pinocamphones 3 , and in some cases, fencholenals 4 were isolated and characterized. A mechanism involving a concerted oxirane ring opening is proposed (Scheme 4).     

Réarrangement de thiénobenzothiépinones en thiénoisothiazolinone et benzoisothiazolinone

Under the conditions of the Schmidt reaction the thienobenzothiepinones 1 , 2 and 13 involve a rearrangement respectively in N-benzythieno[2,3-d]isothiazolin-3-one ( 5 ) and benzoisthiazolin-3-one ( 6 ). A mechanism for this rearrangement is proposed.     

Etude expérimentale et théorique de la substitution de N-méthyl-halogéno-triazoles-1,2,4 par les réactifs nucléophiles

Kinetic studies of the substitution of isomeric N-methyl-halogeno-1,2,4-triazoles with piperidine or the methoxide ion have been carried out. The experimental results show that the 1-mcthyl-5-halogcno isomer is more reactive than the 4-methvl-3-halogeno isomer. Various theoretical treatments of the reaction have been applied. The calculations show that the “frontier charge” and “delocalised bond” models give (he best results.