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ChemicalBook CAS DataBase List 3,6-Dichloro-4,5-dimethylpyridazine
34584-69-5

3,6-Dichloro-4,5-dimethylpyridazine synthesis

4synthesis methods
-

Yield:34584-69-5 53%

Reaction Conditions:

with N-ethyl-N,N-diisopropylamine;trichlorophosphate at 160; for 0.333333 h;Microwave irradiation;

Steps:

9

Description 9; 3,6-Dichloro-4,5-dimethyl-pyridazine (D9); A mixture of 6-hydroxy-4,5-dimethyl-2H-pyridazin-3-one (2.56 g, 18 mmol) (prepared by a procedure similar to that described in WO 99/36407), phosphorus oxychloride (8 ml) and diisopropylethylamine (4 ml) was stirred at 160 0C for 20 min., under microwave irradiation (Biotage MW-oven). The solvent was then partially evaporated in vacuo and remaining material poured into a mixture of cold water, saturated sodium hydrogen carbonate and dichloromethane. The mixture was then basified with portions of sodium hydrogen carbonate until there was no more CO2 evolution. The organic layer was separated, dried (Na2SO4), filtered and the solvent evaporated in vacuo. The residue was purified by column chromatography (dichloromethane / heptane 1/1 to 10/0) to yield D9 (1.7 g, 53 %) as a solid. C6H6Cl2N2 requires 176; Found 177 (MH+)

References:

WO2008/68277,2008,A1 Location in patent:Page/Page column 21

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