Trimethylaluminium (0.72 mL of a 2 M solution in toluene, 1.44 mmol) was added dropwise to a stirred solution of isopropylamine (85 mg, 1.44 mmol) in dioxane (3 mL) at room temperature under argon. After 1 h, a solution of 6-(3-butyl-5-methyl-isoxazol-4-ylmethoxy)-pyridazine-3-carboxylic acid methyl ester (110 mg, 0.36 mmol) in dioxane (3 mL) was added and the reaction mixture heated at 90° C. After 2 h the reaction mixture was cooled in an ice/water bath and quenched with Seignette salt solution (1 mL). The resultant mixture was filtered, the filter cake washed with dichloromethane, then the combined filtrates were concentrated then purified by chromatography (silica, 0 to 80% ethyl acetate in heptane) to give the title compound (45 mg, 38%) as a colourless oil. MS: m/e=333.4 [M+H]+.
