The composition and structure of the intermediate compounds and target product were confirmed by the data of elemental analysis and 1H and 13C NMR spec troscopy (see Experimental). In the 1H NMR spec trum of compound III, the resonances of all protons are observed in the aromatic region at δ= 8.8–6.7 ppm as one singlet, three doublets, and one mul tiplet corresponding to the protons of the phenyl and bipyridyl fragments (Fig. 1a). The ...
[Baxter, Paul N. W.; Connor, Joseph A.; Wallis, John D.; Povey, David C.; Powell, Anne K. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1992 , # 13 p. 1601 - 1606]