A simple route to thermally-stable salts of pyrrolidinium-2-carbonylchloride

none3noThe chlorination of the carboxylic acid unit of alpha-aminoacids is an important reaction in organic synthesis, and the resulting compounds are usually seen as reactive intermediate species. Herein we report a straightforward procedure to obtain [MCl6](-) salts (M = Nb, 2a; Ta, 2b) of the L-proline-derivative (pyrrolidinium-2-carbonylchloride). These are stable up to 80 degrees C, in the solid state as well as in organic solvents. The X-ray structures determined for 2a, b include the first example of a crystallographically-characterized alpha-ammonium-acylchloride.mixedFabio Marchetti;Guido Pampaloni;Stefano ZacchiniFabio Marchetti;Guido Pampaloni;Stefano Zacchin