Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities
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 hydra...
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MDPI AG
2011-02-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/16/2/1834/ |
| _version_ | 1818690481329012736 |
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| author | Sayed M. Riyadh |
| author_facet | Sayed M. Riyadh |
| author_sort | Sayed M. Riyadh |
| collection | DOAJ |
| description | 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-1H-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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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-12-17T12:26:41Z |
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| spelling | doaj.art-9a655f1d9b5242d4ba4067b5acc6430c2022-12-21T21:48:44ZengMDPI AGMolecules1420-30492011-02-011621834185310.3390/molecules16021834Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial ActivitiesSayed M. RiyadhNovel 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-1H-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.http://www.mdpi.com/1420-3049/16/2/1834/(dimethylamino)acryloylpyrazolehydrazonoyl chloridesantitumor activityantimicrobial activity |
| spellingShingle | Sayed M. Riyadh Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities Molecules (dimethylamino)acryloylpyrazole hydrazonoyl chlorides antitumor activity antimicrobial activity |
| title | Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities |
| title_full | Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities |
| title_fullStr | Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities |
| title_full_unstemmed | Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities |
| title_short | Enaminones as Building Blocks for the Synthesis of Substituted Pyrazoles with Antitumor and Antimicrobial Activities |
| title_sort | enaminones as building blocks for the synthesis of substituted pyrazoles with antitumor and antimicrobial activities |
| topic | (dimethylamino)acryloylpyrazole hydrazonoyl chlorides antitumor activity antimicrobial activity |
| url | http://www.mdpi.com/1420-3049/16/2/1834/ |
| work_keys_str_mv | AT sayedmriyadh enaminonesasbuildingblocksforthesynthesisofsubstitutedpyrazoleswithantitumorandantimicrobialactivities |