Elimination of trimethylamine from hydrazonium salts (8, R= Me) is promoted by base (methoxide ion in methanol). The mechanism is characterized as E2 as shown by substituent effects (p=+ 2.57), Br0nsted coefficients, a primary kinetic isotope effect (kH/kD= 2.10), and solvent effects. Variation in the leaving group (8, R= arylmethyl) shows that NN bond cleavage is leas well advanced in the transition state than CH bond breaking. The ...