Citalopam Impurity G

Citalopam Impurity G is a synthetic byproduct arising from the alkylation step in citalopram production, characterized by a substituted phenoxypropanamine core bearing an ethyl group at the 3-position of the benzyl ring and an additional methoxy moiety on the aromatic system. Its structure incorporates an N-methylpiperazine fragment and a fluorinated aryl ether linkage, differing from the parent drug by the ethyl substitution and methoxy appendage. This impurity serves as an HPLC reference standard for quantifying process-related deviations in citalopram active pharmaceutical ingredient batches.