Crystal structure determination of N- and O-alkylated tautomers of 1-(2-pyridinyl)-5-hydroxypyrazole
- 주제(키워드) 13C NMR , 1-(2-Pyridinyl)-5-hydroxypyrazole , Crystal structure , N-Alkylation , O-Alkylation , Tautomerism
- 등재 SCIE, SCOPUS
- 발행기관 Elsevier B.V.
- 발행년도 2020
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000168754
- 본문언어 영어
- Published As https://dx.doi.org/10.1016/j.molstruc.2020.128272
초록/요약
The crystal structure determination of tautomeric products produced by the alkylation of 1-(2-pyridinyl)-3-phenyl-4-propyl-1H-5-hydroxypyrazole 2 was investigated. Treatment of 2 with isopropyloxycarbonyloxymethyl iodide and potassium carbonate under phase-transfer conditions affords two major products out of three possible O-, N-, and C-alkylated tautomers. The tautomeric structures of O-alkylated 3a and N-alkylated 3c were elucidated by means of NMR spectroscopic investigations and confirmed by single crystal X-ray analysis. The single crystal structures of alkylated compounds provide clear difference between the tautomeric pyrazole and pyrazolone ring systems in terms of bond lengths and torsional angles, moreover, conformational changes between two tautomers. © 2020
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