Tandem ESI mass spectrometry of 11α- and 11β-{4-[N,N-bis(2-chloroethyl)amino]phenyl}acetates of the estrane steroids

ESI MS studies showed that the major collision-activated fragmentation pathway of the [M + Na]+ ions of the title estranes involves elimination of NaCl and HCl molecules. Fragmentation of the [M + H]+ ions involves the functional groups, which provides information on their structures. The fragmentation of the [M + Na]+ and [M + H]+ ions was estimated by quantum-chemical calculations.