反应详情

2-Difluoromethoxy-4-hydroxypyridine (123 g, 0.764 mol), 3-chloro-5-methoxypyridazine (110.47 g, 0.764 mol), potassium carbonate (211.18 g, 1.53 mol), CuBr (54.80 g, 0.382 mol) and 18-crown-6 (1 g) were mechanically stirred under nitrogen in diglyme (1.28 L) at 100° C. for 30 h. The mixture was cooled to RT and partitioned between ethyl acetate and 2 L of 3% HCl. The layers were separated. The aqueous layer was then adjusted to pH--1 with conc. HCl and extracted twice with additional ethyl acetate. The combined organics were filtered through silica gel and then extracted twice with 1.5 N NaOH. Solids were formed which were removed by filtering the organic layer through silica gel and celite. The organic layer was dried (MgSO4), filtered through silica gel and evaporated in-vacuo. The residue was triturated with ethyl acetate and filtered to give pure 3-[[2-(difluoromethoxy)-4-pyridinyl]oxy]-5-methoxypyridazine (92.5 g, 45% yield) as a light brown solid, mp=119° C. -120.5° C.

1. custompartitioned between ethyl acetate and 2 L of 3% HCl
2. customThe layers were separated
3. extraction1 with conc. HCl and extracted twice with additional ethyl acetate
4. filtrationThe combined organics were filtered through silica gel
5. extractionextracted twice with 1.5 N NaOH
6. customSolids were formed which
7. customwere removed
8. filtrationby filtering the organic layer through silica gel and celite
9. dry with materialThe organic layer was dried (MgSO4)
10. filtrationfiltered through silica gel
11. customevaporated in-vacuo
12. customThe residue was triturated with ethyl acetate
13. filtrationfiltered