Chloroacetic acid (100 g, 1058.2 mmol) was added slowly and dropwise to a suspension containing tert-butanol (1300 mL) and potassium tert-butanolate (262 g, 2335 mmol) at 30-50 °C. The reaction mixture was heated to 80-85 °C and maintained at this temperature for 6-8 hours. Upon completion of the reaction, it was cooled to 30-45 °C, water (200 mL) was added and subsequently concentrated under reduced pressure. Water (800 mL) was again added at 20-35 °C and washed with methyl tert-butyl ether (MTBE). The pH of the aqueous phase was adjusted to 1.5-3.0 using 4N sulfuric acid solution, after which the product was extracted with MTBE. The organic phase was washed with aqueous sodium chloride solution and the organic phase was concentrated under reduced pressure to give tert-butoxyacetic acid (CTOX) as a liquid product (yield 62.9%; GC purity = 99.38%).1H NMR (400 MHz, CDCl3): δ 7.267 (s, 1H), 4.029 (s, 2H), 1.271 (s, 9H).
