2-Halopyrroles. II. Mass Spectroscopic Studies

The mass spectra of 11 pyrrole derivatives are discussed, with particular reference to the loss of any halogen atom present.

In simple derivatives such as 2-chloropyrrole (1), a loss of halogen is only as favorable as loss of HCN.

In more complex compounds, loss of halogen competes poorly with the other processes such as loss of carbon monoxide, the tropylium species, or methyl groups.

Substantial fragmentation of the pyrrole nucleus was observed before rearrangement of an alkyl pyrrole to a pyridinium species.