Process for preparing l-alpha-aminolactam from a mixture of d-and l-alpha-aminolactam

Claim 1

IN PROCESS FOR PREPARING L-A-AMINOLACTAM FROM A MIXTURE OF D- AND L-A-AMINOLACTAM BY PRECIPITATING, IN A LIQUID MEDIUM, AN OPTICAL ANTIPODE OF A-AMINOLACTAM AS THE SALT OF AN OPTICALLY ACTIVE PYRROLIDONE CARBOXYLIC ACID WITH THE SAME STERIC CONFIGURATION, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF THE STEPS OF FORMING A POLAR SOLVENT SOLUTION OF A MIXTURE OF D- AND L-A-AMINOLACTAM AND AN OPTICALLY ACTIVE COMPOUND SELECTED FROM THE GROUP CONSISTING OF PYRROLIDONE CARBOXYLIC ACID AND AMMONIUM PYRROLIDONATE WHEREIN LESS THAN ONE MOLE OF SAID OPTICALLY ACTIVE COMPOUND IS USED PER MOLE OF SAID A-AMINOLACTAM MIXTURE, AND ADDING SAID POLAR SOLVENT SOLUTION TO A LIQUID MEDIUM IN WHICH THE SALTS OF D- AND L-A-AMINOLACTAM WITH SAID OPTICALLY ACTIVE COMPOUND ARE BOTH SUBSTANTIALLY INSOLUBLE, AND IN THE ABSENCE OF INORGANIC BASES THEREBY FORMING A PRECIPITATE CONSISTING FOR THE LARGER PART OF THE SALT OF SAID OPTICALLY ACTIVE COMPOUND WITH SAID A-AMINOLACTAM WITH THE SAME STERIC CONFIGURATION.