Huemer V, Eller GA, Holzer W. Heterocyclic analogs of xanthiones: 5,6-fused 3-methyl-1-phenylpyrano[2,3-c]pyrazol-4(1H) thiones-synthesis and NMR ((1)H, (13)C, (15)N) data.
MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010;
48:476-482. [PMID:
20474027 DOI:
10.1002/mrc.2609]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Various [5,6]pyrano[2,3-c]pyrazol-4(1H)-thiones were synthesized in high yields by treatment of the corresponding [5,6]pyrano[2,3-c]pyrazol-4(1H)-ones with Lawesson's reagent. Detailed NMR spectroscopic studies were undertaken of the title compounds. Complete and unambiguous assignment of chemical shifts ((1)H, (13)C, (15)N) and coupling constants ((1)H,(1)H; (13)C,(1)H) was achieved by the combined application of various one- and two-dimensional (1D and 2D) NMR spectroscopic techniques. Unequivocal mapping of most (13)C,(1)H spin coupling constants is accomplished by 2D (delta, J) long-range INEPT spectra with selective excitation.
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