Methyl 3-hydroxy-4-methylbenzoate is synthesized by the following steps:The amino ester 35 (60 g, 0.364 mol) was added to dil. H2SO4 (125 ml conc. H2SO4 diluted with 1 L water) and warmed on a water bath until all the compound was dissolved. Cold water (800 ml) was added and the mixture was cooled to 0 °C. NaNO2 (62.6 g, 0.907 mol) was added to this mixture with constant stirring. It was then stirred at room temperature for 15 minutes. Then, urea (65.4 g, 1.09 mol) was added in portions. The mixture was warmed at 50 ºC for 15 minutes (temperature was not allowed to rise above 55 ºC). EtOAc was added to the reaction mixture and washed with brine, dried (anhydrous Na2SO4), filtered and concentrated under reduced pressure to afford a colourless solid (26.56 g).
