4-BROMO-2-FLUOROMANDELIC ACID synthesis

Yield:-

Reaction Conditions:

with caesium carbonate;ethyl iodide in DMF (N,N-dimethyl-formamide) at 20 - 60; for 5.5 h;

Steps:

6.74 Example 6.74: 5-cyano-2-[({5-nitro-6-[4-nitro-2-(trifluoromethyl)phenyl]-1,2-benzisoxazol-3-yl}carbonyl)amino]benzoic acid; preparation of ethyl (4-bromo-2-fluorophenyl)(hydroxy)acetate

This carboxylic acid (20.1 g) was dissolved in DMF (300 mL). Cesium carbonate (27.7 g, 85.0 mmol, Aldrich) and iodoethane (6.25 [ML,] 78.1 mmol, Aldrich) were added, and the reaction was stirred at room temperature for 3 hours and then at [60 °C] for 2.5 hours. The mixture was diluted with MTBE [(1] L) and washed with water (500 mL), saturated [NAHC03] (500 mL), water (2 X 500 mL), and brine (500 mL). The organics were dried over Na2S04, filtered through a 1"plug of silica gel, and evaporated yielding the ethyl ester as 19.8 g of off-white solid. 'H NMR (400 MHz, DMSO-d6, 19F decoupled) 8 ppm 1.13 (t, [J 7.] 15 Hz, 3 H) 4.10 (m, 2 H) 5.29 (d, [J 5.] 60 Hz, [1] H) 6.32 (d, [J=5.] 60 Hz, 1 H) 7.44 (m, 2 H) 7.56 (d, [J=1. 45 HZ, 1 H).]

References:

WO2004/18428,2004,A1 Location in patent:Page 151-152