455 research outputs found

    A facile synthesis of 3-cyclopropyl- and 5-cyclopropyl-isoxazoles

    Get PDF
    The regioselective synthesis of isomeric isoxazoles 3-(2-arylcyclopropyl)-5-methylthio- and 5-(2-arylcyclopropyl)- 3-methylthio-isoxazoles is described

    Reaction of β-oxodithioesters with propargylamine: a facile entry to novel 2-(acylalkylidene)-5-(methylene)thiazolidines

    Get PDF
    Reaction of β-oxodithioesters derived from acyclic and cyclic ketones with propargylamine affords novel 2-(acylalkylidene)-5-(methylene)-thiazolidines in high yields by intramolecular nucleophilic attack of thiocarbonyl sulfur on the triple bond of the β-oxo-N-propargylthioamide intermediates

    Trimethylsilyl chloride assisted conjugate addition-elimination of organocopper reagents to 2-bis(methylthio)nitroethylene: an efficient and highly stereoselective synthesis of 2-methylthio-2-alkyl/aryl-1-nitroethylenes and their application for synthesis of nitroheterocycles

    Get PDF
    An efficient method for the synthesis of novel 2-methylthio-2-alkyl/aryl-1-nitroethylenes 2 has been developed via conjugate addition-elimination of organocopper reagents to nitroketene dithioacetal 1 in the presence of TMSCl. The product nitroethylenes 2 have been further utilized for the synthesis of substituted 3-nitro-2-alkyl/arylpyrroles 5 by their reaction with aminoacetaldehyde dimethylacetal followed by acid catalyzed cyclization in ethereal HCl. The reaction of 2 with propargyl alcohol has also been investigated

    High rate of diabetes in the Asia-Pacific Island: possible role of rapid urbanization: a hospital based study

    Get PDF
    Asia-Pacific countries are experiencing lifestyle-related non-communicable disease crises. Kimbe, one of Papua New Guinea's provincial capitals is noted as the fastest growing city in the South Pacific subcontinent yet its impact on diabetes mellitus (DM) is not known. To determine pattern of newly diagnosed DM, we conducted a retrospective review of Kimbe General Hospital medical admissions from January 2009 to December 2012. 125 patients were diagnosed with diabetes with male: female ratio of 1.1: 1. Overall, number of patients diagnosed with DM at the hospital increased rapidly from 16 in 2009 to 49 in 2012; p <0.05. Majority of the patients were of young population aged <50 years representing 72 % of the cohort and predominantly of coastal province of origin. Almost 3/4th of the study population was based in Kimbe town and its suburb with only 32 subjects (25.6%) identified as rural residents; p<0.05. This study suggests that subjects living in Asia-Pacific area of rapid urbanization are at higher risk of diabetes compared to residents of rural areas. It highlights the need for adequate health planning and education as part of urbanization program in the DM-prone Asia-Pacific population. Further prospective studies are needed to verify our findings

    Preparation of lithium 5-lithiomethy-3-methylpyrazole-1-carboxylate and its reaction with α-oxoketene dithioacetals: a new general method for substituted and annelated pyrazolo[1,5-a]pyridines

    Get PDF
    5-Methylpyrazole derivative 1 is metallated at the C-5 methyl carbon atom to form lithium 5-lithiomethyl-3-methylpyrazole-1-carboxylate 3 which on reaction with α-oxoketene dithioacetals 4a-d, 12a-c and 15a-b yields substituted and annelated pyrazolo[1,5-a]pyridines 7a-d, 13a-c and 16a-b

    Heteroaromatic annulation studies on 2-[bis(methylthio)methylene]- 1-methyl-3-oxoindole: synthesis of novel heterocyclo[b] fused indoles

    Get PDF
    Heteroannulation of 2-[Bis(methylthio)methylene]-1-methyl-3-oxoindole with β- substituted β-lithioaminoacrylonitrile, malononitrile and guanidine has been reported to yield novel substituted pyrido[3,2-b]indoles and pyrimido[5,4-b]indole derivatives in varying yields

    Synthesis of novel 3-arylcyclopenta[c]quinolines via acid-induced domino cyclization of 2-arylamino-2-methylthioethenyl 2-arylcyclopropyl ketones

    Get PDF
    A novel acid-induced domino cyclization of N,S-anilinoacetals of type 3 derived from 2- arylcyclopropyl ketones, is reported which yields a wide range of substituted- and fused- 3- arylcyclopenta[c]quinolines 6 with concomitant formation of a cyclopentane and a quinoline ring
    • …
    corecore