Density functional theory (DFT) and Complete Basis Scale methods (CBS-QB3, G3B3) are used to investigate the reactivity, the mechanism, structure-reactivity relationship and the kinetics of N-methyl-2-pyrrolidinone (NMP) with Cl atom. To obtain rate constants of the reaction, the RRKM theory is employed at atmospheric pressure and temperature range 273–380 K. This study provides the rate coefficients and detailed H-abstraction mechanism for the reaction of Cl with NMP at high level of theoretical methods. The obtained rate constant ~ 0.92 x 10− 10 to 8.98 × 10− 10cm 3 molecule− 1s− 1 at 298 K agreed with those obtained previously for N,N-dimethyl formamide (DMF) and N,N-dimethyl acetamide (DMA). The study shows that the reaction mechanism of Cl with NMP goes favorably through an H-abstraction from N-methyl groups and adjacent CH2. The rates constants obtained for the three amides confirm our prediction regarding the structure-reactivity relationship where 1000/T.