In:
Journal of Heterocyclic Chemistry, Wiley, Vol. 51, No. 4 ( 2014-07), p. 1171-1178
Kurzfassung:
This paper describes an efficient approach for the synthesis of a new series of 6‐[3‐alkyl(aryl/heteroaryl)‐5‐trifluoromethyl‐1 H ‐pyrazol‐1‐yl]nicotinic acids (where alkyl = CH 3 ; aryl = Ph, 4‐OCH 3 Ph, 4,4′‐BiPh; and heteroaryl = 2‐Furyl) from the hydrolysis reaction of alkyl(aryl/heteroaryl)substituted 2‐(5‐trifluoromethyl‐5‐hydroxy‐4,5‐dihydro‐1 H ‐pyrazol‐1‐yl)‐5‐(5‐trifluoromethyl‐5‐hydroxy‐4,5‐dihydro‐1 H ‐1‐carbonylpyrazol‐1‐yl)pyridines, under basic conditions and at 70–95% yields. In a subsequent step, the esterification reaction of pyrazolyl‐nicotinic acids done in thionyl chloride and methanol led to the isolation of a series of methyl 6‐[alkyl(aryl/heteroaryl)‐5‐trifluoromethyl‐1 H ‐pyrazol‐1‐yl] nicotinates as stable hydrochloride salts at 64–84% yields, which could be easily converted to hydrazides to give new oxadiazolyl‐pyrazolyl‐pyridine tricyclic scaffolds at good yields from a [4 + 1] cyclocondensation reaction with 1,1,1‐triethoxyethane and 1‐(triethoxymethyl)benzene as the reagent/solvent.
Materialart:
Online-Ressource
ISSN:
0022-152X
,
1943-5193
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2014
ZDB Id:
2042274-X
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