Hydrochloric Acid → N-(2-hydroxy-3,5-dichlorobenzoyl)-L-phenylalanine

Participants

Reaction Steps

One hundred and eight grams of ethyl ester of N-(2-acetoxy-3,5-dichlorobenzoyl)-L-phenylalanine were dissolved in 1 L of anhydrous ethyl alcohol and placed in a 2 L round bottomed flask equipped with a magnetic stirring bar and placed in water bath at ambient temperature. Into this mixture a solution of 33.33 g of sodium hydroxide in 37.2 mL of water was added in a single portion and the mixture stirred at ambient temperature for 17 h (overnight). A volume of 68.6 mL of concentrated hydrochloric acid was added under stirring, which was maintained for an additional of 2 h. The precipitated sodium chloride was filtered off and the filtrate evaporated to dryness at 60° C. under 30 T of pressure. The residue of 88.9 g (98% yield) solidified after cooling in form of a colorless glassy product, which was well soluble in toluene or acetonitrile, thereby producing an OTA template (e.g., for use in MIP-OTA production). MS: M+354 and 356 1H NMR (CDCl3, ppm): 12.2 very broad s, 1H, 7.49 d, J 2.4, 1H, 7.35-7.28 m, 3H, 7.20 d, J 2.0, 1H, 7.18-7.16 m, 2H, 6.80 br d, J 6.4, 1H, 6.4 very broad s, 1H, 5.07 dd, 5.2 and 5.2, 1H, 3.34 dd, J 14.0 and 5.2, 1H, 3.27 dd, J 13.6 and 5.2, 1H.

Provenance & Evidence