Potassium Hydroxide → 1-Methyl-5-[4'-(trifluoromethyl)[1,1'-biphenyl]-2-carboxamido]-1h-indole-2-carboxylic acid potassium salt

Participants

Reaction Conditions

Reaction Steps

A solution of potassium hydroxide (54.1 g) in water (600 mL) was added over 15 minutes to a suspension of ethyl 1-methyl-5-[4′-(trifluoromethyl)[1,1′-biphenyl]-2-carboxamido]-1H-indole-2-carboxylate (300 g), from the previous step, in propan-2-ol (4500 mL) at 60° C. and the resulting mixture was heated to reflux for an hour. The solution was seeded with product (1-methyl-5-[4-(trifluoromethyl)[1,1′-biphenyl]-2-carboxamido]-1H-indole-2-carboxylic acid potassium salt) and the mixture granulated at 60-70° C. for two hours. The mixture was slowly cooled to 0-5° C. and the product potassium salt collected by filtration, washing with a chilled 90/10 mixture of propan-2-ol and demineralized water (510 mL total volume). The product solids were dried, yielding 1-methyl-5-[4′-(trifluoromethyl)[1,1′-biphenyl]-2-carboxamido]-1H-indole-2-carboxylic acid potassium salt 2.6 hydrate (287.4 g, 85% correcting for water content of 9.1% by weight). Anhydrous Mol wt of parent acid (calc) 438.41, MS: 439.3 (MH+), 437.3 (M−). 1H NMR (DMSO-d6): δ 3.99 (s, 3H), 6.53 (s, 1H), 7.12-7.76 (complex, 11H), 10.05 (broad), HPLC retention time 9.30 minutes. The preferred solid form of the product is characterized by the pXRD (powder X-ray diffraction) pattern shown in FIG. 7.

Provenance & Evidence