The paper presents the study of kinetic interaction of an ester molecule (Methyl Butanoate) and long chain alkane (n-Heptane). It was found that the present mechanism for Methyl butanoate (MB) over predicts the extinction strain rates in a counter flow diffusion flames by almost a factor of 5. The corrected and improved mechanism in this paper for MB predicts the extinction strain rates to within 5% of experiment values. It is also found that these rates are very sensitive to the transport parameters. A combined mechanism developed for n-heptane (nH) and Methyl butanoate (MB) predicts the extinction strain rates and flame speeds to within 5% including their blends. The extinction strain rate varies linearly from with blending fraction of MB, decreasing as MB mole fraction is increased maintaining total mole fraction of nH and MB constant. This shows that MB reduces the reactivity of n-Heptane. The combined mechanism is used to study the kinetic interaction between MB and nH. The early formation of CO2 in MB and its effect on soot precursors has also been investigated.