Navegando por Palavras-chave "ultrasound irradiation"

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    Improved synthesis of benzotriazoles and 1-acylbenzotriazoles by ultrasound irradiation
    (Bentham Science Publ Ltd, 2007-01-01) Pereira, Claudio M. P.; Stefani, Helio Alexandre [UNIFESP]; Guzen, Karla P.; Orfao, Aline T. G.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Some 1H-benzotriazoles have been synthesised in good yields in short times by reaction of o-phenylenediamine with sodium nitrite in acetic acid under ultrasound irradiation. Also, the ultrasound-assisted preparation of 1-acylbenzotriazoles is described.
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    A mild and efficient method for halogenation of 3,5-dimethyl pyrazoles by ultrasound irradiation using N-halosuccinimides
    (Elsevier B.V., 2005-10-03) Stefani, H. A.; Pereira, CMP; Almeida, R. B.; Braga, R. C.; Guzen, K. P.; Cella, R.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    The 4-halo-3,5-dimethyl pyrazoles have been synthetisized in good yields in short reaction times in the absence of a catalyst by reaction of 3,5-dimethyl pyrazoles with N-halosuccinimides (NBS, NCS and NIS) under ultrasound irradiation. Finally, the halogenation of pyrazoles with Br-2, ICI and I-2 was showed in similar conditions. (c) 2005 Elsevier B.V. All rights reserved.
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    Ultrasound enhanced synthesis of 1,5-benzodiazepinic heterocyclic rings
    (Elsevier B.V., 2006-11-13) Guzen, Karla P.; Cella, Rodrigo; Stefani, Helio A.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    1,5-Benzodiazepines are synthesized by a reaction of o-phenylenediamines with a diketone or ketones series by ultrasound irradiation in presence of APTS. the condensation occurred in a mild condition with good to excellent yields. (c) 2006 Elsevier B.V. All rights reserved.