A Novel electrophilic reagent, 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulphonyl-2, 1,3-benzoxadiazole (DBD-COCI) for fluorometric detection of alcohols, phenols, amines and thiols

A novel electrophilic reagent for alcohols, phenols, amines and thiols, 4‐(N‐chloroformylmethyl‐N‐methyl)amino‐7‐N,N‐dimethylaminosulphonyl‐2, 1, 3‐benzoxadiazole (DBD‐COCI) was synthesized. The reactivity of the reagent to these nucleophiles was studied using high‐performance liquid chromatography (HPLC) with precolumn derivatization techniques. DBD‐COCI reacted in benzene solution at the room temperature or 60°C with androsterone (a representative of hydroxyls), (−)‐mandelic and D,L‐lactic acid (hydroxy acid), estrone (phenol), benzylamine (primary amine), phenetidine (aromatic amine) and α‐mercapto‐N,2‐naphthylacetamide (thiol) to give fluorescent products bearing fluorescence wavelengths at between 543 nm and 555 nm (excitation at between 437 nm and 445 nm). The base catalyst, quinuclidine was required to complete the reaction with the nucleophiles except aromatic amines. The reaction solution was subjected to a reversed phase HPLC and the detection limits of the derivatives were at the femto mol range on column.