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Síntese de BIS-1H-pirazóis trialometil substituídos / Synthesis of trihalomethyl substituted BIS-1H-pyrazolesCechinel, Cleber André 03 October 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present research describes the use of b-alcoxyvinyl trihalomethyl ketones
(1,2) [CX3C(O)CHCRR1, where X: Cl, F; R: H, Me, Ph, 4-MePh, 4-MeOPh, 4-FPh, 4-
ClPh, 4-BrPh, 4-NO2Ph, 4,4 -Biphenyl, 1-Naphtyl, 2-Furyl, 2- Thienyl; R1: OMe, OEt] in
the regioselective synthesis of Oxalyl-1,1 -Bis-5-trihalomethyl-5-hydroxy-4,5-dihydro-
1H-pyrazoles (6,8), Succinyl-1,1 -Bis-5-trihalomethyl-5-hydroxy-4,5-dihydro-1Hpyrazoles
(10,14), Succinyl-1-(5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H)-pyrazole-
1 -(5-trichloromethyl-5-hydroxy-4,5-dihydro-1H)-pyrazole (13) e Carbonyl-1,1 -Bis-5-
trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole (16), obtained from the
cyclocondensation reaction of 1,1,1-trihalo-4-alkoxy-3-alken-2-ones (1,2) and dihydrazide
oxallyc, di-hydrazide succinic and carbohydrazide, respectively. For the
synthesis of these compounds, ethanol was used as solvent, at temperature of 50-80 oC,
in reaction time of 2-16 hours, with yields of 51-91%.
The Bis-5-hydroxy-4,5-dihydro-1H-pyrazolines (6,8,10,14,16) were submitted
the dehydration reactions carried out in thionyl choride, pyridine, benzene, at temperature
of 0-80 oC, giving the aromatic compounds Oxalyl-1,1 -Bis-3-aryl-5-trihalomethyl-1Hpyrazoles
(7,9) and Succinil-1,1 -Bis-5-trihalomethyl-1H-pyrazoles (11,15), with yields
of 53-78%. Also, were obtained a series of Carbonyl-1,1 -Bis-5-trihalomethyl-1Hpyrazoles
(3,5), in direct synthesis, thus, in one pot method, from the vinyl trihalomethyl
ketones (1,2) and 1,3-diaminoguanidine hydrochloride, carried out in ethanol/water,
reaction time of 4-5 hours, with yields of 62-86%.
Finally, 5-trifluoromethyl-5-hydroxy-4,5-dihydro-1-succinilhydrazino-1Hpyrazole
(12) and 5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-
carbohydrazide (18), were chemoselectively synthesized, in mild conditions reactions and
using ethanol as solvent , in reaction time of 4 hours, with yields of 44-86%, respectively.
The cyclocondensation reaction of the compounds (12,18) using vinyl trihalomethyl
ketones (1) with di-hydrazide succinic or carbohydrazide, and in molar ratio of 1:1. The
compounds were characterized by spectral and analytical experiments of 1H s and 13C s
NMR, X-Ray Difraction, and the purity were demonstrated by elemental analyzes. / A presente tese descreve a utilização de �-alcoxivinil trialometil cetonas (1,2)[CX3C(O)CHCRR1, onde X: Cl, F; R: H, Me, Ph, 4-MePh, 4-MeOPh, 4-FPh, 4-ClPh, 4-BrPh, 4-NO2Ph, 4,4 -Bifenil, 1-Naftil, 2-Furil, 2- Tienil; R1: OMe, OEt] na síntese regiosseletiva de Oxalil-1,1 -Bis-5-trialometil-5-hidróxi-4,5-diidro-1H-pirazóis (6,8), Succinil-1,1 -Bis-5-trialometil-5-hidróxi-4,5-diidro-1H-pirazóis (10,14), Succinil-1-(5-trifluormetil-5-hidróxi-4,5-diidro-1H)-pirazol-1 -(5-triclorometil-5-hidróxi-4,5-diidro-
1H)-pirazol (13) e Carbonil-1,1 -Bis-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazol (16),obtidos a partir de reações de ciclocondensação entre 1,1,1-trialo-4-alcóxi-3-alquen-2-
onas (1,2) e di-hidrazida oxálica, di-hidrazida succínica e carbohidrazida, respectivamente. Para a síntese destes compostos foi utilizado etanol como solvente, a temperatura de 50-80ºC, em tempo reacional de 2-16 horas, com rendimento de 51-91%. As Bis-5-hidróxi-4,5-diidro-1H-pirazolinas (6,8,10,14,16) foram submetidas a condições de desidratração, utilizando metodologia que emprega cloreto de tionila, piridina e benzeno como meio reacional, à temperatura de 0-80 oC, conduzindo a
obtenção dos compostos aromatizados Oxalil-1,1 -Bis-3-aril-5-trialometil-1H-pirazóis
(7,9) e Succinil-1,1 -Bis-5-trialometil-1H-pirazóis (11,15), com rendimentos de 53-78%.
Também, foram obtidos Carbonil-1,1 -Bis-5-trialometil-1H-pirazóis (3,5) a partir da
síntese direta, ou seja, em passo reacional único, entre as vinil cetonas trialometiladas
(1,2) e cloridrato de 1,3-diaminoguanidina, em etanol/água, em tempo reacional de 4-5
horas, com rendimentos de 62-86%.
Finalmente, foram sintetizados por metodologia quimiosseletiva os produtos 5-
trifluormetil-5-hidróxi-4,5-diidro-1-succinilhidrazino-1H-pirazol (12) e 5-trifluormetil-5-
hidróxi-4,5-diidro-1H-pirazol-1-carbohidrazida (18), em condições reacionais mais
brandas e que utilizaram etanol como solvente, em tempo reacional de 4 horas, com
rendimentos de 44-86%, respectivamente. As reações de ciclocondensação dos
compostos (12,18) empregaram vinil cetonas trifluormetiladas (1) com di-hidrazida
succínica ou carbohidrazida e em relação molar de 1:1. Os compostos foram
caracterizados por experimentos de RMN de 1H e13C {H}, Difração de Raios-X e sua
pureza determinada via Análise Elementar.
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