1-Bromo-2-methylbutane → 4-((3,5-dimethylisoxazol-4-yl)methoxy)-N-(5-isopropylpyridin-2-yl)-N-(2-methylbutyl)benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-((3,5-dimethylisoxazol-4-yl)methoxy)-N-(5-isopropylpyridin-2-yl)benzenesulfonamide (156 mg, 0.389 mmol) in acetonitrile (4 mL) stirred in air at 20° C., was added 2-(tert-butyl)-1,1,3,3-tetramethylguanidine (133 mg, 0.777 mmol). The reaction mixture was stirred at 20° C. for 1 hour, then 1-bromo-2-methylbutane (117 mg, 0.777 mmol) was added. The reaction then heated by microwaves to 150° C., for 30 minutes. After cooling the solvent was removed in vacuo and diluted with ethyl acetate. The organic phase was washed with water (5 mL), then dried using a hydrophobic frit. The solvent was removed in vacuo to give the crude product as an orange oil. Purification of the crude was attempted using flash silica (Si) chromatography (0-25% ethylacetate-cyclohexane gradient) followed by mass directed autoprep (ammonium carbonate modifier), however impurities still remained. A final purification using a silica (Si) cartridge (eluting with a gradient of 0-25% ethyl acetate-cyclohexane) provided a small amount of clean product (8.5 mg) as a colourless oil. LCMS (2 min, High pH) Rt 1.48 mins, m/z (ES+) 472 (M+H).

Provenance & Evidence