反应详情

To a solution of 1.25 g (4.60 mmol) of the product of Example 19 (as the hydrochloride salt) in 10 mL of acetic acid-water (11:3) was added 0.75 g (5.35 mmol) of hexamethylenetetramine. The mixture was refluxed for 3 h then treated with 6 mL of water and 3 mL of conc. hydrochloric acid. Heating was continued for 10 min at which point the reaction mixture was cooled and concentrated in vacuo to remove the acetic acid. The residue was partitioned between EtOAc and water, and the aqueous layer was separated and extracted. The combined organic layers were washed with brine, dried (Na2SO4), filtered and evaporated. The product was purified on a silica gel flash chromatography column eluted with 5% EtOAc-hexane. Evaporation of the purified fractions and drying in vacuo afforded the title compound.

1. temperatureThe mixture was refluxed for 3 h
2. temperatureHeating
3. temperaturewas cooled
4. concentrationconcentrated in vacuo
5. customto remove the acetic acid
6. customThe residue was partitioned between EtOAc and water
7. customthe aqueous layer was separated
8. extractionextracted
9. washThe combined organic layers were washed with brine
10. dry with materialdried (Na2SO4)
11. filtrationfiltered
12. customevaporated
13. customThe product was purified on a silica gel flash chromatography column
14. washeluted with 5% EtOAc-hexane
15. customEvaporation of the purified fractions
16. customdrying in vacuo