It has been found that several advantages result from working in an aqueous solution at a some- what higher pH (9.0) and a slightly elevated temperature (40') and from employing only an equivalent amount of FDNB: a more rapid reac- tion can be achieved, ethanol evaporation and extraction of excess FDNB can be eliminated and a purer product results with greater economy of reagents. By means of this simplified proced~re,~ we have prepared in crystalline form ...
