Dissertação
β-Enaminonas, 5-hidróxi-4,5-diidropirazóis e 5-Hidróxi-4,5-diidroisoxazóis halometilsubstituídos: estudo molecular por difração de raios-x
Fecha
2008-08-08Registro en:
CAMPOS, Patrick Teixeira. β-Enaminones, 5-hydroxy-4,5-dihydropyrazole and 5-hydroxy-4,5-dihydroisoxazole halomethyl Substituted: molecular study by x-ray Diffractometry. 2008. 187 f. Dissertação (Mestrado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2008.
Autor
Campos, Patrick Teixeira
Institución
Resumen
The molecular study by X-ray diffraction of β-aminovinyl ketones
[R3C(O)CH=C(R1)N(R4R5), onde R3 = CF3, CCl3, CHCl2; R1 = H, Me; R4 = H; R5 =
benzyl, Ph, 5-methylisoxazol-3-yl; R4, R5 = -(CH2)4-, -(CH2)2O(CH2)2-], methyl 5-
hydroxy-5-trihalomethyl-4,5-dihydro-1H-pyrazole-1-carboxylate [3-(R1), 4-(R2), and 5-
(R3) substituted, where R1 = H, Me; R2 = H, Me; R3 = CCl3, CF3], 1-cyanoacetyl-5-
trifluorometyl-5-hydroxy-4,5-dihydro-1H-pyrazole [3-(R1) and 4-(R2) substituted,
where R1 = H, Ph; R1, R2 = -(CH2)4-, R2 = H] and 5-triclorometyl-5-hydroxy-4,5-
dihydroisoxazole [3-(R1) substituted, where R1 = Ph, 4Br-Ph, tien-2-yl] were reported.
The β-aminovinyl ketones have showed the fragment O=C-C=C-N essentially plane,
as well as, the heterocyclic rings 4,5-dihydropyrazole and 4,5-dihydroisoxazole. The
shorter bond lengths of b-aminovinyl ketones indicated an eletronic resonance effect
in the conjugated system O=C-C=C-N. This effect also was encountered in the
double bond N2=C3 of the rings 4,5-dihydropyrazole and 4,5-dihydroisoxazole and
the substituent of the 3-position of this rings, when this substituent was an aromatic
ring. In general, the molecules studied have its crytalline packing governed by intraand
intermolecular hydrogen bond.