Methyl 6-[(3-isobutoxy-5-isopropoxybenzoyl)amino]-3-pyridinecarboxylate (230 mg, 0.62 mM) was dissolved in THF (8 ml) and a 2M NaOH solution (1.2 ml, 2.40 mM) was added. Water (7 ml) was added to the reaction mixture until it became monophasic. The reaction was stirred for 6 hours at ambient temperature and was then acidified to pH=1 with 1N aqueous HCl. The white solid which precipitated from the mixture was isolated by filtration and dried to give the title compound as a colourless solid (195 mg); H1 NMR δ (d6-DMSO) 0.99 (6H d) 1.12 (6H d) 2.00 (1H sept) 3.80 (2H d) 4.65 (1H sept) 6.62 (1H s) 7.19 (2H s) 8.30 (2H s) 8.86 (1H s) 11.09 (1H s br); [M+H]373; [M−H] 371.
