A practical protocol for the preparation of a parallel solution-phase library of 5-arylidene imidazolone is reported. Target compounds were obtained in good yield, stereoselectively, and purity by one-pot domino reaction from various thiohydantoines, arylaldimines, and halogenoalkanes. Purification of the final products by recrystallization with a mixture of pentane/ethanol allowed simple isolation of the 17 components of the array.