Novel
N-arylpyrazole-containing enaminones
2a,b were synthesized as key intermediates. Reactions of
2a,b with active methylene compounds in acetic acid in the presence of ammonium acetate afforded substituted pyridine derivatives
5a-d. Enaminones
2a,b also reacted with aliphatic amines such as hydrazine hydrate
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Novel
N-arylpyrazole-containing enaminones
2a,b were synthesized as key intermediates. Reactions of
2a,b with active methylene compounds in acetic acid in the presence of ammonium acetate afforded substituted pyridine derivatives
5a-d. Enaminones
2a,b also reacted with aliphatic amines such as hydrazine hydrate and hydroxylamine hydrochloride to give bipyrazoles
8a,b and pyrazolylisoxazoles
9a,b, respectively. On the other hand, treatment of
2a,b with a heterocyclic amine and its diazonium salt yielded the respective [1,2,4]triazolo[4,3-
a]pyrimidines
12a,b and pyrazolylcarbonyl[1,2,4]triazolo-[3,4-
c][1,2,4]triazines
14a,b. Moreover, 2-thioxo-2,3-dihydro-1
H-pyrido[2,3-
d]pyrimidin-4-one (
17) was prepared
via reaction of enaminone
2a with aminothiouracil (
15). Cyclocondensation of
17 with the appropriate hydrazonoyl chlorides
18a-c gave the corresponding pyrido[2,3-
d][1,2,4]triazolo[4,3-
a]pyrimidin-5-ones
21a-c. The cytotoxic effects of compounds
2b,
14a and
17 against human breast cell line (MCF-7) and liver carcinoma cell line (HEPG2) were screened and in both lines they showed inhibition effects comparable to those of 5-fluorouracil, used as a standard. The antimicrobial activity of some products chosen as representative examples was also evaluated.
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