2-Chlorobenzaldehyde (o-chlorobenzaldehyde) is an organic compound with the formula . It is one of three isomeric monochlorinated benzaldehyde. 3-Chlorobenzaldehyde and 4-chlorobenzaldehyde are the other isomers. Whereas benzaldehyde is prone to autoxidation, the 2-chloro derivatives are more air-stable.
It is produced by hydrolysis of 2-chlorobenzal chloride:[1]
2-Chlorobenzaldehyde is used in production of CS gas. It reacts with malononitrile to form CS.[2]