Risk Assessment and Safety Evaluation Study for Ozonolysis of β-Pinene: Raw Material of a Novel Prostaglandin D2 Receptor Antagonist S-5751

Safety evaluation for ozonolysis of beta-pinene was conducted using DSC, ARC, and RC1e. ARC measurement showed that the concentration of the ozonized mixture affects its thermal stability. The sample at a high concentration of 1.83 mol/L was very unstable even at room temperature and decomposed rapidly. ADT(24) of the diluted sample of 0.73 mol/L was 28.2 degrees C. Although reductive decomposition of the ozonized mixture at extremely low temperature is very dangerous because of accumulation of the heat of reaction, its process temperature was validated to not exceed the ADT(24). As a result, pilot manufacturing on a 300-L reactor scale could be achieved.