Process for producing nitrilotriacetonitrile

It is disclosed that nitrilotriacetonitrile can be produced in improved yield and purity and at a rapid rate from ammonium sulfate, formaldehyde and hydrogen cyanide by employing a particular order of combination of reactants and maintaining certain critical temperature conditions during the combination and in other portions of the process and while avoiding the presence of HCN vapor in the system. It is disclosed that undesired color frequently encountered in nitrilotriacetonitrile and in derivatives thereof such as trisodium nitrilotriacetate monohydrate and aqueous solutions thereof can be avoided to a large extent without requiring inordinately long processing periods. When using the proper sequence of combination and conditions, the reactants can be combined directly in about stoichiometric proportions without deliberately prolonging or extending the period of addition of reactants. An important aspect of the process is avoiding the presence of free hydrogen cyanide and maintaining a vapor free reaction system until substantially all free HCN is reacted.