Potassium tert-butoxide → 6-[4-({[3-(2,6-Dichlorophenyl)-5-(1-methylethyl)-4-isoxazolyl]methyl}oxy)phenyl]-2-quinolinecarboxylic acid potassium salt

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Reaction Steps

A stirred suspension of 6-[4-({[3-(2,6-dichlorophenyl)-5-(1-methylethyl)-4-isoxazolyl]methyl}oxy)phenyl]-2-quinolinecarboxylic acid (179 g, 0.335 mol) in ethanol (2.6 L) was treated with 1 N potassium tert-butoxide in tert-butyl alcohol (350 mL) and stirred at room temperature under N2 for 1 hour. The mixture was then heated to a gentle reflux for 2 hours and was stirred overnight at room temperature. The suspension was filtered, then the filter cake was washed with hexane, combined with 5 g of similarly prepared material and dried at 60° C. in a vacuum oven overnight to yield 6-[4-({[3-(2,6-dichlorophenyl)-5-(1-methylethyl)-4-isoxazolyl]methyl}oxy)phenyl]-2-quinolinecarboxylic acid potassium salt as a beige solid (181 g, 84%). 1H NMR (400 MHz, DMSO-d6): 8.25 (d, J=9 Hz, 1H), 8.18 (d, J=9 Hz, 1H), 8.08 (d, J=2 Hz, 1H), 8.02 (d, J=8 Hz, 1H), 7.94 (dd, J=2, 9 Hz, 1H), 7.68 (d, J=9 Hz, 2H), 7.62 (d, J=8 Hz, 2H), 7.53 (dd, J=7, 9 Hz, 1H), 6.90 (d, J=9 Hz, 2H), 4.86 (s, 2H), 3.46 (m, 1H), 1.32 (d, J=7 Hz, 6H). ES-LCMS m/z 533 (M+H)+.

Provenance & Evidence