Chloroacetophenones

Formula : C8-H7-Cl-O
CAS : 1341-24-8 

A Potent eye, throat, and skin irritant. One of its uses is as a riot control agent.

Chloroacetylferrocene

Formula :
CAS : 51862-24-9 

Reacts stoichiometrically with papain to form ferrocenopapain, an inactive form of papain.