The following is an introduction to 2-Bromo-4-butanolide CAS 5061-21-2, I hope to help you better understand 2-Bromo-4-butanolide CAS 5061-21-2. 2-Bromo-4-butanolide CAS 5061-21-2 is a transparent colorless to pale yellow liquid, which can be used as a pharmaceutical intermediate.