Microwave assisted synthesis of 5-hydroxy-5-trichloromethyl-4,5-dihydroisoxazoles
摘要:
A series of 13 5-hydroxy-5-trichloromethyl-4,5-dihydroisoxazoles have been synthesized in 78-96% yield by environmentally benign microwave induced techniques involving the cyclocondensation of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones [CCl3C(O)C(R-2)=C(R-1)OR, where R-2=H, alkyl; R-1=H, alkyl, aryl and R=H, alkyl] with hydroxylamine using toluene as solvent. The advantages obtained by the use of microwave irradiation in relation to a classical method were demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved.
Regiospecific acylation of acetals. A convenient method to obtain β-methoxyvinyl trichloromethyl ketones
摘要:
The regiochemistry of the acylation of enol ethers, generated in situ, from acetals of unsymmetrical ketones is reported. These results demonstrate a convenient one-pot method to obtain a series of beta-methoxyvinyl trichloromethyl ketones [CCl3COCH=C(OMe)R, where R=Et, n-Bu, i-Pr, (CH2)(2)C(OMe)=CHC(O)CCl3 and (CH2)(5)CO2CH3)] in high yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
A simple and convenient one-pot procedure for the synthesis of 5- and 6-substituted 2-phenyl-3 H-pyrimidin-4-ones by the condensation of 4-alkoxy-1,1,1-trichloroalk-3-en-2-ones with benz-amidine hydrochloride is described.
Microwave assisted synthesis of 5-hydroxy-5-trichloromethyl-4,5-dihydroisoxazoles
作者:Marcos A.P Martins、Paulo Beck、Wilson Cunico、Claudio M.P Pereira、Adilson P Sinhorin、Rogério F Blanco、Rodrigo Peres、Helio G Bonacorso、Nilo Zanatta
DOI:10.1016/s0040-4039(02)01555-1
日期:2002.9
A series of 13 5-hydroxy-5-trichloromethyl-4,5-dihydroisoxazoles have been synthesized in 78-96% yield by environmentally benign microwave induced techniques involving the cyclocondensation of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones [CCl3C(O)C(R-2)=C(R-1)OR, where R-2=H, alkyl; R-1=H, alkyl, aryl and R=H, alkyl] with hydroxylamine using toluene as solvent. The advantages obtained by the use of microwave irradiation in relation to a classical method were demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved.
Regiospecific acylation of acetals. A convenient method to obtain β-methoxyvinyl trichloromethyl ketones
作者:Marcos A.P. Martins、Giovani P. Bastos、Helio G. Bonacorso、Nilo Zanatta、Alex F.C. Flores、Geonir M. Siqueira
DOI:10.1016/s0040-4039(99)00672-3
日期:1999.6
The regiochemistry of the acylation of enol ethers, generated in situ, from acetals of unsymmetrical ketones is reported. These results demonstrate a convenient one-pot method to obtain a series of beta-methoxyvinyl trichloromethyl ketones [CCl3COCH=C(OMe)R, where R=Et, n-Bu, i-Pr, (CH2)(2)C(OMe)=CHC(O)CCl3 and (CH2)(5)CO2CH3)] in high yields. (C) 1999 Elsevier Science Ltd. All rights reserved.