N-TERT-BUTOXYCARBONYL-2-PYRROLIDINONE AND PROCESS FOR PRODUCING THE SAME

N-tert-butoxycarbonyl-2-pyrrolidinones of the following formula (1): [wherein, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 represent each independently a hydrogen atom, halogen atom, cyano group, optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, optionally substituted linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted amino group, -OR a group, or -SR b group, R a and R b represent each independently a hydrogen atom, alkylcarbonyl group having 2 to 10 carbon atoms, arylcarbonyl group having 7 to 20 carbon atoms, aralkyl group having 7 to 20 carbon atoms, alkoxyalkyl group having 2 to 10 carbon atoms, trialkylsilyl group having 3 to 10 carbon atoms, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms, alternatively, R 1 and R 2 may be connected to form a >C=O group together with a carbon atom to which they are connected, R 3 and R 4 may be connected to form a >C=O group together with a carbon atom to which they are connected, R 5 and R 6 may be connected to form a >C=O group together with a carbon atom to which they are connected, any two of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 may be connected to form an optionally substituted polymethylene group having 1 to 4 carbon atoms, one or no-mutually-adjacent two methylene groups constituting the polymethylene group may be substituted by an oxygen atom, one or two ethylene groups constituting the polymethylene group may be substituted by a vinylene group, no-mutually-adjacent two methylene groups constituting the polymethylene group may be mutually connected via an oxygen atom, methylene group, ethylene group or vinylene group.].