Feasibility of the thermodynamically controlled synthesis of amoxicillin

The enzymatic, thermodynamically controlled synthesis of amoxicillin in aqueous solution was measured in order to study the feasibility of a 'solid-to-solid' conversion. In aqueous solution, however, the synthetic yield of amoxicillin remains lower than the amoxicillin solubility. Therefore, a 'solid-to-solid' synthesis of amoxicillin in aqueous solution is not feasible. Synthetic yields in enzymatic condensation reactions can often be improved by adding organic solvents in monophasic systems. Addition of cosolvents is calculated to improve the apparent equilibrium constant of amoxicillin synthesis considerably, but probably not the synthetic yield, due to solubility restrictions of the reactants. (C) 1998 Elsevier Science B.V. All rights reserved.