Synthesis of 3-(5-amino-1 H -1,2,4-triazol-3-yl)propanamides and their tautomerism.

Autor:	Lim FPL; School of Pharmacy, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway Selangor Darul Ehsan 47500 Malaysia dolzhenkoav@gmail.com anton.dolzhenko@monash.edu +60-3-5514-6364 +60-3-5514-5867., Tan LY; School of Pharmacy, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway Selangor Darul Ehsan 47500 Malaysia dolzhenkoav@gmail.com anton.dolzhenko@monash.edu +60-3-5514-6364 +60-3-5514-5867., Tiekink ERT; Research Centre for Crystalline Materials, School of Science and Technology, Sunway University Bandar Sunway Selangor Darul Ehsan 47500 Malaysia., Dolzhenko AV; School of Pharmacy, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway Selangor Darul Ehsan 47500 Malaysia dolzhenkoav@gmail.com anton.dolzhenko@monash.edu +60-3-5514-6364 +60-3-5514-5867.; School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University GPO Box U1987 Perth Western Australia 6845 Australia.
Jazyk:	angličtina
Zdroj:	RSC advances [RSC Adv] 2018 Jun 19; Vol. 8 (40), pp. 22351-22360. Date of Electronic Publication: 2018 Jun 19 (Print Publication: 2018).
DOI:	10.1039/c8ra04576c
Abstrakt:	Two complementary pathways for the preparation of N -substituted 3-(5-amino-1 H -1,2,4-triazol-3-yl)propanamides (5) were proposed and successfully realized in the synthesis of 20 representative examples. These methods use the same types of starting materials viz . succinic anhydride, aminoguanidine hydrochloride, and a variety of amines. The choice of the pathway and sequence of the introduction of reagents to the reaction depended on the amine nucleophilicity. The first pathway started with the preparation of N -guanidinosuccinimide, which then reacted with amines under microwave irradiation to afford 5. The desired products were successfully obtained in the reaction with aliphatic amines (primary and secondary) via a nucleophilic opening of the succinimide ring and the subsequent recyclization of the 1,2,4-triazole ring. This approach however failed when less nucleophilic aromatic amines were used. Therefore, an alternative pathway, with the initial preparation of N -arylsuccinimides and their subsequent reaction with aminoguanidine hydrochloride under microwave irradiation, was applied. The annular prototropic tautomerism in the prepared 1,2,4-triazoles 5 was studied using NMR spectroscopy and X-ray crystallography. Competing Interests: There are no conflicts to declare. (This journal is © The Royal Society of Chemistry.)
Databáze:	MEDLINE
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