Methylamine → (2Z)-4-(Methylamino)-4-oxo-2-butenoic acid

Participants

Reaction Steps

The same reactor as used in Example 7 was adopted. This reactor was charged with a solution 53 g of maleic anhydride in 200 g of chlorobenzene. Then, methylamine gas was blown in gradually and piecemeal at 30° C. at a rate of 4.3×10-3 mol/min. over a period of two hours to produce a white slurry of N-methyl maleinamic acid. Subsequently, the slurry and 22.5 g of ortho-phosphoric acid (purity 89% by weight), 0.1 g of phenothiazine, and 0.02 g of zinc acetate added thereto were heated at 134° C. for two hours to effect reaction. Thereafter, the resultant reaction mixture was cooled to 40° C., filtered, and distilled under a vacuum to expel chlorobenzene. Consequently, there was obtained 45 g of light yellow N-methyl maleimide having purity of 92.1% by weight. The yield of the product is calculated to be 72.5 mol% based on methylamine as the raw material.

Provenance & Evidence