presence of DABCO (1,4-diazabicyclo[2.2.2]octane) and TBAB (tetrabutylammonium bromide) undergo a facile intramolecular N2-double-alkylation to form pyrrolidine and piperidine ring derivatives under solvent-free conditions. Moreover, the alkylation of acyl hydrazide with 1,6-dibromohexane as substrate produced the related N2-mono-alkylated derivatives under the same conditions. Interestingly, using K2CO3