The preparation, structure, and reactivity of methyl 3,3-bis(4-(dimethylamino)pyridinium-l-yl)propenoate dichloride (1) are discussed. 1 tetrachloride (2) was converted to 1 with formic or acetic acid in methanol. A mechanism for the conversion of 2 to 1 is suggested. Hydrolysis of 1 under basic conditions gave 3,3-bis(4-(dimethylamino)pyridinium-l-yl)propenoic acid (3), which has a pKa of 2. The X-ray structure of 1 shows that the pyridinium rings are both twisted with respect to the double bond; the resulting high steric hindrance prevent Diels-Alder reactions with dienes despite the electrophilic nature of the system. © 1990, American Chemical Society. All rights reserved.