Preparation and cyclisation reactions of 3-Carboxy-4-naphthylbut-3-enoic Acids

The condensation of naphthalene-1- or 2-carbaldehyde with dimethyl 2,2-dimethyl-succinate (Stobbe conditions) gives predominantly the ( Z )-hemiesters 3 and 11a . The hemiester 3 contains a small amount of the ( E )-isomer. Similar condensation of naphthalene-2-carbaldehyde with dimethyl-2-methylsuccinate gave the hemiester ( E )- 12a . Their configuration and the ratios of the ( Z:E )-hemiesters, their derived acids, anhydrides, indenones and phenanthrene derivatives are inferred by high resolution ¹H-n.m.r. spectroscopy.     

Elaboration of enriched margarine with lentisk oil and honey: Formulation,characterization, and monitoring of oxidative stability

This study focused on the use of lentisk oil and honey as natural sources to formulate margarine with ameliorated quality and oxidative stability. For this, five margarines were formulated with honey and different concentrations of lentisk oil. Analyses were performed on oil and honey used, and then physicochemical characterization and several oxidative stability tests were applied to assess margarine quality. The results showed a significant richness of lentisk oil and honey in total phenolics and total flavonoids and expressed good antioxidant activities. As well as the evaluation of oxidative stability of enriched margarines during 3 months of storage demonstrated that margarine added with 2% lentisk oil (M1) had the best resistance properties and longer Rancimat induction time (22.26 h), better than the control and margarines added with 5% (M2), 10% (M3), and 15% (M4) lentisk oil. Globally, margarines prepared with high concentrations of lentisk oil (M2–M4) were not different from the control, whereas only M1 was permitted to ameliorate the stability of margarine with a slight influence on physicochemical parameters. The elaboration of margarine supplemented with 2% lentisk oil improves the properties of the product, which could then be applied to margarine manufacturing.     

Activated nitriles in heterocyclic synthesis: A Novel Synthesis of Pyrimidine Derivatives

The reaction of 3-amino-2,4-diethoxycarbonylcrotononitrile with cinnamonitrile derivatives afforded the pyrimidines 5a--d and not the pyridines 4 as expected from literature. Similarly pyrimidines 5e--h were produced when 3-amino-2,4-dicyanocrotononitrile was treated with the same reagent. The structure was established based on MS and high resolution ¹H-n.m.r. spectroscopy.     

Machine learning and smart card based two-factor authentication scheme for preserving anonymity in telecare medical information system (TMIS)

Neural Computing and Applications - Telecare medical information system (TMIS) is used to connect patients and doctors who are at a different location from each other. The authentication of the...     

Nitriles in Organic Synthesis: Synthesis of new pyridazine,pyridine and pyrazolo[3,4-b]pyridine derivatives

The reaction of diethyl monoiminomalonate with benzoylacetonitrile affords the ethyl 3-amino-4-cyanopentanoate derivative 1 a . Compound 1 a condensed with salicylaldehyde to yield the coumarin 5 and coupled with arenediazonium salts to yield the arenehydrazones 6a – c . Compounds 6a , b could be converted into the aminopyridazinium carboxylate 8a , b on treatment with aqueous sodium hydroxide. The reaction of 6a – c with hydrazine and phenyl hydrazine is reported.     

Reactivity of the exocyclic double bond in 4-arylidene-2-phenyl-2-imidazolin-5-ones toward organomagnesium compounds. II

4-Arylidene-2-phenyl-2-imidazolin-5-ones 1 react with Grignard reagents in a boiling ether-benzene mixture to yield 4-diarylmethyl derivatives 2 together with their oxidation products 3 and 4 . The exocyclic double bond in 5 also undergoes addition reaction with the same reagents to yield 4-triarylmethyl derivatives 6 . Alkylation of 2 affords the 4-alkylimidazolones 7 and 8 .