[Annulated heterocycles from methyl 6-chloro-5-formyl-2-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3-carboxylate].
The pyridone 1a reacts with POCl3/DMF to yield the title compound 2a. After irradiation of 2a the enolether 3 is isolated, as shown by an X-ray structure determination. The pyridine 4 obtained by dehydrogenation of 2a leads under reductive conditions to the benzo[c][2,7]naphthyridines 5-7. The reaction of 4 with o-phenylenediamine gives the benzimidazole 8, while using 2-aminophenol or 2-aminothiophene respectively the pyrido[2,3-b[1,5]benzoxazepine 11 and the corresponding benzothiazepine 12 are obtained.
Görlitzer
K
K
Institut für Pharmazeutische Chemie der Technischen Universität Braunschweig, Germany. k.goerlitzer@tu-bs.de
Enge
C H
CH
Jones
P G
PG
D006571:Heterocyclic Compounds / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D008958:Models, Molecular; D009574:Nitro Compounds / Q000138:chemical synthesis*; D011725:Pyridines / Q000138:chemical synthesis*; D014961:X-Ray Diffraction
D006571:Heterocyclic Compounds; D007202:Indicators and Reagents; D009574:Nitro Compounds; D011725:Pyridines; C508308:methyl 6-chloro-5-formyl-2-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3-carboxylate