Amino resins are an important class of resins with diverse applications in the paints and coatings industry. Butylated urea formaldehyde (BUF) resins are amino resins whose end use is directly dependent upon the precise control of its properties. Here, we develop a holistic approach through which we tune BUF chemistry, pH, and reactor conditions to predict the evolution of various resin properties like molecular weight, alkoxy functionalization, degree of butylation, and so forth. Specifically, we develop a reaction mechanism for the condensation step and rate kinetics for a semibatch reactor using a generic framework. Furthermore, we perform end-to-end simulations of BUF synthesis, together with the kinetics of the addition step, and use experiments to determine rate constants and model validation. Through our simulations, we demonstrate the synthesis of BUF with targeted properties like resin with high alkoxy functionalities. As our approach is derived from fundamental chemistry, it can significantly contribute toward the "on-demand" synthesis of resins, designed for a particular application.