Asymptotic analysis of a complex reaction, Claisen condensation, is discussed. Under certain assumptions related to experimental observations the kinetics scheme of the reaction can be considerably reduced. Additional complications in the problem arise due to the fact that one of the substances is present in a sparingly soluble solid phase. We show how reductions for increasingly complex systems with kinetics, mass transfer and feed can be systematically handled by employing the methodology of asymptotic analysis. Generalizations of the reduction approach for the case of an arbitrary number of fast intermediate reactions are also considered.The identification of model parameters is considered with aid of the reduced systems. Questions of parameter estimation and optimal design of experiments are discussed using the MCMC methods. (C) 2003 Elsevier Science Ltd. All rights reserved.