Dimethyl Acetylene Dicarboxylate

All articles of this category Introduction Dimethyl acetylene dicarboxylate (DMAD) is an electron-deficient alkyne diester widely used as dienophile and dipolarophile in cycloaddition reactions. It is used as a standard in Diels-Alder reactions to check the efficiency of various dienes. It can undergo [2+2] cycloaddition ­reactions, [ 1 ] 1,3-dipolar cycloaddition with 1,3-dipoles, for example azides, [ 2 ] diazoalkanes, nitrile oxide, carbonyl ylides, [ 3 ] and azomethine ylides. Besides it is also a powerful Michael acceptor and can accept various nucleophiles, for example nitrogen, oxygen, carbon, sulfur, and phosphorus. DMAD is inexpensively available, and it can be prepared from maleic acid via a bromination-dehydrohalogenation sequence to furnish acetylene dicarboxylic acid, [ 4 ] which, upon esterification with methanol using sulfuric acid, gives dimethyl acetylene dicarboxylate. [ 5 ] Scheme 1