Explanation and prediction of the selective crystallization of boscalid by mid-frequency Raman difference spectroscopy analysis

The selective crystallization behaviours of amorphous boscalid (BOS), BOS monohydrate and acetone/ethyl acetate/ethanol/methanol solutions were explained and predicted by mid-frequency Raman difference spectroscopy analysis. The phase transition processes including solution to amorphous BOS, solution to BOS monohydrate, and amorphous BOS to Form I were explained, predicted and realized. Also, suitable preparation routes for different BOS phases with good purities were proposed.