Yield:-

Reaction Conditions:

Stage #1:ethyl 4-methylpyrimidine-5-carboxylate with water;sodium hydroxideReflux;
Stage #2: with hydrogenchloride in water at 25 - 28;

Steps:

[229] Intermediate: 53: 4-methylpyrimidine-5-carboxylic acid: Intermediate 52 (2.6 g, 15.64 mmol) dissolved in sodium hydroxide solution (1.88 g, 47 mmol in 4 ml water) and refluxed. The reaction mixture was cooled to rt and acidified with con HCl to obtain the solid. Solid that obtained was filtered and dried to obtain the title compound (1.5 g) as an yellow solid. -NMR (δ ppm, DMSO-i , 400 MHz): 13.5 (bs, 1H), 9.14 (s, 1H), 9.05 (s, 1H), 2.71 (s, 3H).

References:

ICOZEN THERAPEUTICS PVT. LTD.;RHIZEN PHARMACEUTICALS S.A.;MUTHUPPALANIAPPAN, Peyyappan;VISWANADHA, Srikant;MERIKAPUDI, Gayatri, Swaroop;VAKKALANKA, Swaroop, Kumar, V.S. WO2011/42797, 2011, A1 Location in patent:Page/Page column 69-70