Teixeira, FatimaLucas, CarlaCurto, Maria João MarceloTeixeira, António P. S.Duarte, M. TeresaAndre, Vania2016-02-232016-02-232016Teixeira, F.C.; Lucas, C.; Curto, M. João M.; Teixeira, A.P.S.; Duarte, M.T.; André. Novel Bisphosphonates Derived from 1H-Indazole, 1H-Pyrazolo[3,4-b]Pyridine, and 1H-Pyrazolo[3,4-b]Quinoline. In: Heteroatom Chemistry, 2016, Vol. 27, nº 1, p. 3-111098-1071http://hdl.handle.net/10400.9/2867Novel tetraethyl ethylene-1,1-bisphosphonate esters derived from 1H-indazole, 1H-pyrazolo[3,4-b]pyridine, and 1H-pyrazolo[3,4-b]quinoline were synthesized by a Michael addition reaction of tetraethyl ethylidene-1,1-bisphosphonate with the corresponding heterocycle, using conventional heating and microwave-assisted methods. The microwave-assisted method provides shorter reaction times and better yields. The hydrolysis of bisphosphonates afforded the corresponding bisphosphonic acids or salt, using concentrated hydrochloric acid or TMSBr/collidine, respectively. All new compounds were fully characterized, and their structures were assigned using 1H, 31P, and 13C NMR and IR spectroscopies and mass spectrometry. The molecular structure of compound 6 was confirmed by X-ray diffraction studies.engBisphosphonatesIndazolePyrazolo[3,4-b]pyridinePyrazolo[3,4-b]quinolineMicrowave-assisted reactionjournal article10.1002/hc.21282