Summary The secondary product in the sulfonation of cinnamic acid has again been shown to be m-sulfocinnamic acid by its preparation from m-bromo- cinnamic acid, the identity of the products being established by the identity of numerous derivatives. The true o-sulfocinnamic acid has been prepared (for the first time) and its difference from the foregoing compound completely demonstrated. The addition of sodium bisulfite to the double bond has been shown to be ...
