New synthesis of 1,1-substituted hydrazines by alkylation of N-acyl- or N-alkyloxycarbonylaminophthalimide using the Mitsunobu protocol

N-acyl- and N-alkoxycarbonylaminophthalimides are prepared using a convenie nt reaction and are efficiently used as acid partners in Mitsunobu reaction . This reaction allows them to be alkylated by primary, secondary or benzyl groups. Comparison of the reactivities and pK(a) values of these N-substit uted aminophthalimides suggest that the success of the Mitsunobu reaction i n this case seems to be governed more by steric than by electronic effects. A final dephthaloylation step results in an efficient method for the prepa ration of 1,1-substituted hydrazines.