Orthoamide. LIV [1] Beiträge zur Chemie azavinyloger Orthoamid‐Derivate der Ameisensäure

Orthoamides. LIV. Contributions to the Chemistry of Azavinylogous Orthoformic Acid Amide Derivatives The azavinylogous aminalester 3 reacts with primary amines to give amidines 5 and 6 . In the reaction of 3 with aniline the azavinylogous amidine 7 is produced additionally to the amidine 5c . Ethylendiamine is formylated at both aminogroups, the bis‐amidine 8 thus formed is transformed to the salts 9a , b . Benzoxazole and benzimidazole can be prepared from 3 and o‐aminophenol and o‐phenylenediamine, resp. carboxylic acid amides, urea, thiourea, aromatic acid hydrazides 17 and the sulfonylhydrazide 19 are formylated by 3 at nitrogen to give N‐acylated formamidines 14 , 16 , 18 , 20 . From 3 and aliphatic acid hydrazides 17 and alkylhydrazines, resp., can be obtained 1,2,4‐triazole 21 and 1‐alkyl‐1,2,4‐triazoles 22a , b , resp. N,N‐dimethylcyanacetamide ( 32 ) reacts with 3 and the orthoamide 4a , resp., to give a mixture of the formylated compound 34 and the amidine 33 . The reaction conditions are of low influence on the ratio in which 33 and 34 are formed. The orthoamide 4b and 32 react to afford a mixture of the amidine 35 and the enamine 36 . Hydrogensulfide acts on 3 giving N,N‐dimethylthioformamide ( 37 ). From 3 and 1‐alkynes 41 can be prepared the amidines 42 . Hydrolysis of 42b affords phenylpropiolaldehyde ( 43 ). The alkylation of the aminalester 3 gives rise to the formation of vinylogous amidiniumsalts 1c and 1d , resp., additionally is formed the amide acetal 2a . The salt 1d can also be prepared from 3 and borontrifluoride‐ether. Iodide reacts with N,N‐dimethylformamide acetals 12a , b in an unclear, complicated manner giving orthoesters 53 , N,N‐dimethylformamide, alkyliodides, alcohols, ammoniumiodides 46 and carbondioxide. The action of halogens on 3 affords the salts 1a , b , c , e , f depending on the chosen stoichiometric ratio. Aromatic aldehydes are suited for trapping azavinylogous carbenes formed on thermolysis of 3 — 1,3‐oxazoles 69 are the reaction products. From 3 and propionaldehyde the amidine 65 can be obtained with low yield. Carbondisulfide transforms 3 to the azavinylogous salt 66 . The preparation of the azavinylogous orthoamide 4a is described. The thermolysis of 3 and 4a , resp., gives rise to the formation of the triaminopyrimidine 67 . Treatment of 1a with lithiumdiisopropylamide affords the triaminopyrazine 68 , which can also be obtained by thermolysis of 3 in the presence of sodium hydride. Azavinylogous carbenes are thought to be the intermediates.     

A finite element method for flow in compression molding of thin and thick parts

Based on Barone and Caulk's model and a generalized variational functional, a finite element simulation was developed for the compression molding of thin and thick parts. For solving the u-v-p type equations, an element-based penalty method and a mixed formulation were implemented. Numerical results show that the new model gives better accuracy in velocity and velocity gradient than the Hele-Shaw formulation for cases where both models are appropriate. Predictions of velocity and its gradient by the model are compared with other FEM results and BEM solutions. Using a fixed base mesh that covers the mold cavity, a new technique was developed for tracking the moving flow front. Temporary elements and nodes are generated for the filled part of elements intersected by the flow front. This method allows a smooth representation of the flow front and has exact boundary conditions on the flow front. The scheme is demonstrated for compression molding of an elliptical and an L-shaped charge.     

Prototype implementation of fast and secure traceability service over public networks

Internet communication message protocol (ICMP)‐based traceability methods are widely used to trace packets over the Internet; however, in their attacks, adversaries likewise use ICMP packets. Furthermore, the lack of security in ICMP‐based traceability results in failures for many current traceability methods. Moreover, current routers are unable to provide extended services to Internet users and applications. To address this need, our laboratory has introduced the service‐oriented router (SoR). SoR is middleware that can be implemented on a Cisco AXP and Juniper JunosV App Engine. In this paper, we propose a secure method of providing packet traceability over public networks using SoR features. We implemented a secure packet traceability service prototype on the ns‐3 simulator. The test results conclude that there is a maximum additional cost of 48.69 and 123.91 μs of processing overhead per packet in each hop when the proposed secured traceability service is used with a 128‐bit key space in AES‐GCM and AES‐CTR modes, respectively. Moreover, for 256‐bit key spaces, AES‐GCM and AES‐CTR modes consumed additional 47.18 and 123.25 μs, respectively, over the plain traceability. Yet, from the evaluations on the test bed topology, it clearly shown that the proposed method was 79% faster than the conventional trace route method in providing the secured end‐to‐end traceability. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Beiträge zur Synthese von Orthocarbonsäureamiden

The formamidinium salts 11a, c as well as the nitrile 12 react with sodiumhydride/dimethylamine in the presence of trimethylborate to give the ortho formic acid amide 3a . The orthoamides 6a and 16 can be prepared from the iminium salts 15 and 14 , resp. by the same procedure. Treatment of the azavinylogous formamidinium salt 15 with sodiumhydride and piperidine or morpholine in the presence of trime‐thylborate affords the orthoamides 6c and 6d , resp. By transamination of the azavinylogous aminalester 5a are accessible the orthoamides 6b—d . The vinylogous orthocarbonic acid derivative 17 can be obtained from the salt 14 and sodium alcoholates. The action of sodiumhydride, dimethylamine and trimethylborate on the iminium salt 18 produces a mixture of the orthocarbonic acid derivatives 7a, 8a, 9a . When the guanidinium salt 20 is treated with the same reagents the ortho‐amides 3a and 10a are obtained. The reduction of the salt 20 with sodiumhydride in the presence of several activating reagents (e.g. tetrabutyl orthotitanate, aluminiumisopropylate, trimethylborate) affords the orthoamide 3a . The reduction of the iminium salts 18 and 24 does not proceed clean, giving mixtures of various orthoformic acid derivatives. The form‐amidine 25 can be prepared by reduction of the salt 15 with sodiumhydride/trimethylborate with good yields. By the action of the corresponding carbanions on the guanidinium salt 20 can be obtained the carboxylic acid orthoamides 26—33 . By the same procedure the orthoamides of alkyne carboxylic acids 36a—h, j—n are accessible.