Benzylidene compounds are, formally speaking, derivatives of benzylidene, although few are prepared from the carbene. Benzylidene acetal is a protecting group in synthetic organic chemistry of the form PhCH(OR)<sub>2</sub>. For example, 4,6-O-benzylidene-glucopyranose is a glucose derivative. Benzylidene is an archaic term for compounds of the type PhCHX<sub>2</sub> and PhCH= substituents (Ph = C<sub>6</sub>H<sub>5</sub>). For example, dibenzylideneacetone is (PhCH=CH)<sub>2</sub>CO. Benzal chloride, PhCHCl<sub>2</sub>, is alternatively named benzylidene chloride.
Benzylidene is the molecule C<sub>6</sub>H<sub>5</sub>CH. It is a triplet carbene (CAS RN 3101-08-4). It is generated by irradiation of phenyldiazomethane.