Studies of the Interesting Gas‐phase Rearrangement Reactions of 2‐Pyrimidinyloxy‐N‐arylbenzylurea Promoted by Urea‐Carbamimidic Acid Tautomerism by ESI‐MS/MS and Theoretical Computation

The gas-phase rearrangement reactions of compound 1, 2-dimethoxypyrimidinyloxybenzylaminoben- zenedipropylurea, were studied by ESI-MS/MS. The experimental results showed that introduction of dipropylurea moiety into the molecule initiated various interesting gas-phase chemistries and the mechanisms were proposed on the basis of hydrogen/deuterium (H/D) exchange experiments and theoretical computations. Moreover, product 2, the solution-phase rearrangement product of compound 1, was synthesized and its gas-phase chemistries were also studied to support the propos gas-phase rearrangement reactions of compound 1.