2-Chloropropanal is a chlorinated aldehyde with the molecular formula C3H5ClO. It is a colorless to pale yellow liquid with a pungent odor. This compound is highly reactive due to the presence of both an aldehyde group and an alpha-chlorine atom, making it a versatile and important building block in organic synthesis. Its primary application is as a key intermediate in the synthesis of various pharmaceuticals and agrochemicals. For instance, it serves as a crucial precursor in the production of the herbicide metolachlor and its enantiomer S-metolachlor. It is also used in the synthesis of amino acids like L-alanine and other fine chemicals. The reactivity of the chloromethyl group adjacent to the carbonyl allows for further functionalization through nucleophilic substitution or elimination reactions. Due to its high reactivity, 2-chloropropanal is lachrymatory, corrosive, and a severe irritant to skin, eyes, and the respiratory system. It must be handled with appropriate personal protective equipment in a well-ventilated fume hood. It is typically stored under inert conditions at low temperatures to prevent polymerization or decomposition.