R. Bryant, F.-A. Kunng, M. S. South
Sep 1, 1995
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0
Influential Citations
19
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
A large scale synthesis of 3-chloro-5-methoxypyridazine was developed (18 moles) that relies on the protection of the pyridazinone nitrogen of 4,5-dichloro-3(2H)-pyridazinone as the tetrahydropyranyl derivative 2. The 5-chloro position of the protected pyridazinone was selectively displaced with methoxide to give 3 followed by catalytic hydrogenation of the 4-chloro group to give 4. Removal of the protecting group with acid followed by phosphorous oxychloride treatment gave the target compound 6 in good yield. This route is superior to the previously described synthesis of this compound.