The acylated dielectrophilic precursors were cyclized with dinucleophiles hydroxylamine, hydrazine, semicarbazide and thio semicarbazide to form the corresponding 5-trifluoromethyl-4,5-dihydroisoxazoles, 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles and trifluoromethyl-1H-pyrazole in good yields (>80%).
Os precursores acilados dieletrofílicos foram ciclizados com dinucleofilos hidroxilamina, hidrazina, semicarbazida e tiosemicarbazida formando os respectivos 5-trifluorometil-4,5-diidroisoxazóis, 5- trifluorometil-4,5-diidro-1H-pirazóis e trifluorometil-1H-pirazóis em bons rendimentos (>80%).
The reactions of cyclocondensation employed 2-trifluoroacetyl-1- metoxycycloalkenes and five different 1,2-dinucleofiles (hydroxylamine, hydrazine hydrochloride, acetic hydrazine, semicarbazide and 4-hydrazine-7-chloroquinoline), leading to yield between 34,85%.
As reações de ciclocondensação empregaram 2-trifluoracetil-1- metoxicicloalquenos e cinco diferentes 1,2-dinucleófilos, hidroxilamina, cloridrato de hidrazina, hidrazina acética, semicarbazida e 4-hidrazina-7-cloroquinolina, levando a rendimentos entre 34,85%.
Two 4-methoxy-4-(4-fluorophenyl)-1,1,1-trihalo-3-buten-2-ones were submitted to the reactions with four dinucleophile: semicarbazide hydrochloride, thiosemicarbazide, methyl hydrazinocarboxylate and 2-furoic hydrazide furnishing, eigth new 1-substituted-3-(4-fluorophenyl)-5-trihalomethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles (63,98%).
Duas 4-metoxi-4-(4-fluorfenil)-1,1,1-trialo-3-buten-2-onas foram submetidas a reações com quatro dinucleófilos: cloridrato de semicarbazida, tiosemicarbazida, carboximetilhidrazina e 2-furanoilhidrazina, originando inicialmente 8 novos 3-(4-fluorfenil)-5-trialometil-5-hidroxi-4,5-diidro-1H-pirazóis (63,98%).
in this module it was also accomplished a study about the synthetic potential of 4-metoxy-1,1-dichloro-3-penten-2-one as a CCC block in cyclizations [3,2] with hydrazine hydrochloride, phenylhydrazine hydrochloride, semicarbazide hydrochloride, aminoguanidine hydrochloride, and dimethylhydrazine dihydrochloride to leave to a series of 5-dichloromethyl-3-methyl-1Hpyrazoles.
Também é abordado nesse trabalho um estudo do potencial sintético da 4-metoxi-1,1-dicloro-3-penten-2-ona na síntese de uma série de 5-diclorometil-3-metil-1H-pirazóis, através da reação com cloridrato de hidrazina, cloridrato de fenilidrazina, cloridrato de semicarbazida, cloridrato de aminoguanidina e dicloridrato de dimetilidrazina.
The reactivity and regiochemistry of the α-chlorinated β-enamino compounds was assessed through the study of cyclization reactions involving the coupling of these substrates with dinucleophiles such as hydrazine and semicarbazide derivatives.
A reatividade dos centros eletrofílicos dos β-enamino compostos α-clorados foi estudada em reações de ciclização, reagindo-se estes compostos frente a dinucleófilos como hidrazinas e semicarbazida, avaliando-se o padrão de reatividade destes compostos e a regioquímica dos sistemas heterocíclicos polifuncionalizados 3 e 4 obtidos.