Methanol → 5H-Indeno(1,2-b)pyridin-5-one

See general oxidation method of Sprinzak, J. Am. Chem. Soc., 80 (1958) 5449. 4-Azafluorene (5.0 g, 30 mmol) was dissolved in 50 mL anhydrous pyridine containing in solution 2 mL Triton B solution (prepared by evaporating 5 mL of 40% Triton B in methanol (Aldrich Chemical, Inc.) and 5 mL pyridine with heat and reduced pressure followed by q.s. to 10 mL with pyridine). Then air was continuously bubbled through the solution with stirring. An addition of 2 mL Triton B solution was made twice more at two-hour intervals. After six hours the reaction mixture was evaporated to dryness. The residue was triturated in 30 mL water and extracted four times with ethyl acetate (total volume 200 mL). The combined ethyl acetate extracts were dried over anhydrous sodium sulfate. After filtration and evaporation, the residue was chromatographed (silica gel and chloroform) to yield after evaporation of the solvent 4.5 g (83%) of (28). m.p. 132°-136° C. (reported 142° C.).

1. customThen air was continuously bubbled through the solution
2. additionAn addition of 2 mL Triton B solution
3. waitwas made twice more at two-hour
4. customAfter six hours the reaction mixture was evaporated to dryness
5. customThe residue was triturated in 30 mL water
6. extractionextracted four times with ethyl acetate (total volume 200 mL)
7. dry with materialThe combined ethyl acetate extracts were dried over anhydrous sodium sulfate
8. filtrationAfter filtration and evaporation
9. customthe residue was chromatographed (silica gel and chloroform)
10. customto yield
11. customafter evaporation of the solvent 4.5 g (83%) of (28)
12. customm.p. 132°-136° C. (reported 142° C.)

ORD record

ord-cfcf17d622d5433eaff29eab49c49907

Source dataset

uspto-grants-1989_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04864028