5-Chloromethylfurfural

5-Chloromethylfurfural is an organic compound with the formula C4H2O(CH2Cl)CHO. It consists of a furan substituted at the 2- and 5-positions with formyl (CHO) and chloromethyl (CH2Cl) groups. CMF, as it is called, is obtained by dehydration of fructose and other cellulose derivatives using hydrochloric acid. It is a colourless liquid. It can be reduced to give 5-methylfurfural, and can be hydrolyzed to give hydroxymethylfurfural.

Typical nitrile gloves do not protect against CMF. The compound, even when handled as a solid, can absorb through gloves and stain the skin a dark brown black color. The health implications of dermal CMF exposure are unclear; CMF should be handled with caution.