[F:1][CH:2]([F:11])[O:3][C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[CH:6][N:5]=1.Cl[C:13]1[N:14]=[N:15][CH:16]=[C:17]([O:19][CH3:20])[CH:18]=1.C(=O)([O-])[O-].[K+].[K+]>COCCOCCOC.C1OCCOCCOCCOCCOCCOC1>[F:11][CH:2]([F:1])[O:3][C:4]1[CH:9]=[C:8]([O:10][C:13]2[N:14]=[N:15][CH:16]=[C:17]([O:19][CH3:20])[CH:18]=2)[CH:7]=[CH:6][N:5]=1
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.
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