Thermal behaviour of HMS/RDX mixtures is studied by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). It has been found that the temperature of polymorphic transformation of HMX shows an increase due to the presence of RDX. The enthalpies of the enothermic transformations depend on the composition of the mixture, and up to 30% RDX there is a linear relationship. The formation of an eutectic with a composition of 30/70 (HMX/RDX) is postulated to explain the melting processes.
A synthesis of N-benzylidene-2-furanamines 8 by means of cyanide addition to acylchalcones 2, followed by piperidine-catalyzed cyclization in the presence of an aldehyde is reported. The 2-pyrrolones 4 are formed together with the compounds 8. In the absence of an aldehyde no furan is obtained. The intermediate 2-ary1-3-benzoyl-4-0~0-4-phenylbutanenitriles 3 are easily isolated. The N-benzylidene-2-furanamines 9 are obtained from the oxonitriles 5. Synthese von Heterocyclen, XXXVIIII). -Funfring-Heterocyclen durch Cyclisierung von 3-Benzoyl-4-oxobutannitrUenEs wird ii ber eine Synthese von N-Benzyliden-2-furanaminen 8 durch Cyanid-Addition an Acylchalkone 2 und nachfolgende, durch Piperidin katalysierte Cyclisierung in Gegenwart eines Aldehyds berichtet. Dabei entstehen die 2-Pyrrolone 4 neben den Verbindungen 8. In Abwesenheit eines Aldehyds bildet sich kein Furan. Die als Zwischenstufen auftretenden 2-Aryl-3-benzoyl-4-0x0-4-phenylbutannitrile 3 kbnnen leicht isoliert werden. Die N-Benzyliden-2-furanamine 9 werden aus den Oxonitrilen 5 gewonnen.The previous paper in this series') describes the preparation of 2-pyridinethiones from suitable a$-unsaturated ketones and cyanoethanethioamide. In this paper we report the synthesis of furanamines and pyrrolones by cyclization of the adducts resulting from cyanide addition to a$-unsaturated ketones 2.The compounds 2, prepared by Knoevenagel condensation of 1 with aromatic aldehydes, easily undergo at room temperature a conjugate addition of cyanide anion to give the 3-benzoyl-4-oxobutanenitriles 3 in high yields ( Table 1). According to a recently described synthesis of substituted 2-furanamine~~~~), cyclization of similar 4-oxobutanenitriles leads to formation of a 2-furanamine ring. However, the behaviour of 3 proved to be quite different. Treatment with piperidine in ethanol, gave rise to 2-pyrrolones 4, together with 2,4-diaryl-4-oxobutanenitriles 5. The latter compounds are formed from 3 by a retro-Claisen elimination, and their structure was confirmed by preparing them from cyanides and the chalcones 6 . Table 1 collects the yields and physical and analytical data of the new compounds 3 and 4 thus obtained, and the corresponding spectroscopic data are listed in Table 2. The cyan0 (2220 -2225 cm-') and the carbonyl(1680 -1695 cm-') bands of compounds 3 and the carbonyl (about 0 VCH Verlagsgesellschaft mbH, D-6940 Weinheim, 1985
Uber die Anwendung des AMl-und PM3-Verfahrens fur energiereiche VerbindungenDas neue semiempirische Verfahren MNDO-PM3 (PM3), eingefiihrt von Stewart, wird verglichen mit dem bekannten AM I-Verfahren (Austin I Modell), eingefuhrt von Dewar, zur Berechnung nitro-substituierter Verbindungen und einiger energiereicher Materialien. Das PM3-Verfahren leistet mehr als das AM1-Verfahren. Die AbstoBung zwischen einsamen Elektronenpaaren wird besser beschrieben mit dem PM3-Leve1, und die bei der AMI-Methode iibliche systematische Korrektur mit ca. -9 kcal/mol fur jede C-NO,-Gruppe betragt dann +3,5 kcal/mol beim PM3-Level. Die Ergebnisse mit PM3 fur N-N0,haltige Verbindungen sind direkt vergleichbar mit den experimentell im Gaszustand erhaltenen Werten. SummaryStewart's new semi-empirical method MNDO-PM3 (PM3) is compared with the well known Dewar's AM1 method in the study of nitro substituted compounds, and some energetic materials. PM3 method shows better performances than the AM1 one. Adjacent lone pairfione pair repulsion are better described at PM3 level and the known systematic correction of about -9 kcal/mol for each C-NO, group of the AM1 method becomes +3.5 kcal/mol at PM3 level. PM3 results for N-NO, containing compounds are directly comparable with experimental gasphase data. 33 De I'utilisation des methodes AM1 et PM3 sur des composes energetiquesLa nouvelle rnethode semi-empirique MNDO-PM3 (PM3) introduite par Steward est comparee B la cCl2bre nikthode AM1 de Dewar pour le calcul de composts nitrosubstituks et de quelques matCriaux CnergCtiques. La mCthode PM3 est plus performante que la mtthode AM1. La rCpulsion entre des paires dClectrons isolCes est mieux dCcrite avec la mCthode PM3: la correction systCmatique usuelle d'env. -9 kcal/mol pour chaque groupe C-NO, de la mtthode AM1 devient +3,5 kcal/mol si l'on utilise PM3. Les rksultats obtenus avec PM3 pour des composCs contenant le groupe N-NO, sont directement comparables aux valeurs obtenues experimentalement i M a t gazeux.
Diaryl‐ and Alkylaryl‐substituted 2‐aminofurancarboxylates have been obtained as Schiff bases 5,6 by cyclization of 2‐ethoxycarbonyl‐4‐oxonitriles 3,4; which result from hydrogen cyanide addition to ethyl α‐acylcinnamates 1,2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.