title: [Tetracyclic derivatives of diltiazem from aurones and thioaurones].
abstract: Tetracyclic derivatives of diltiazem from aurones and thioaurones Heating the aurones 1a, b and the thioaurones 1c, d with 2-aminothiophenol in polyphosphoric acid (PPA) under nitrogen yields the 6,12-dihydrobenzofuro[2,3-c][1,5]benzothiazepines 3a,b and the sulfur analogues 3c, d, respectively. Reaction of the annulated benzofuranes 3a,b with 2-chloroethyl-N,N-dimethylammonium chloride and potassium carbonate leads to S-alkylation and ring opening forming the 3-imino-aurones 5. The tetracycles 3 react with sodium hydride in DMF under ring contraction to afford the benzofuro- and benzothieno[3,2-b]quinolines 6. The stability of the partially saturated tetracycles 3 is investigated by anodic oxidation using the rotating platinum electrode by means of differential pulse voltammetry. The measured half wave potentials of the 1,4-dihydropyridine partial structure in compounds 3 are compared with that of nifedipine.
authors.affiliation: Institut für Pharmazeutische Chemie der Technischen Universität Braunschweig, Germany. k.goerlitzer@tu-bs.de
authors.forename: K
authors.initials: K
authors.lastname: Görlitzer
authors.forename: M
authors.initials: M
authors.lastname: Wichers
mesh_terms: D000478:Alkylation; D001572:Benzofurans / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003500:Cyclization; D004110:Diltiazem / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D004355:Drug Stability; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009543:Nifedipine / Q000737:chemistry; D010084:Oxidation-Reduction; D011083:Polycyclic Compounds / Q000138:chemical synthesis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001572:Benzofurans; D007202:Indicators and Reagents; D011083:Polycyclic Compounds; D004110:Diltiazem; D009543:Nifedipine
vernacular_title: Tetracyclische derivate des diltiazems aus auronen und thioauronen.