To address the challenges of predicting chemical reaction outcomes in computational chemistry, this paper proposes the Broad Reaction Set (BRS), which contains 20 common reaction templates based on SMARTS, and ProPreT5, the first language model capable of handling these templates. ProPreT5 is a T5-based model that improves generalization performance through a novel augmentation strategy for SMARTS templates. Trained with augmented templates, ProPreT5 demonstrates stronger prediction performance and generalization to novel reactions than existing methods.