アルキル化剤としてのMannich塩基に就いて (第3報)

2-Acetamidothiazole類のMannich反応

抄録

Various Mannich bases with dialkylaminomethyl group in the 5-position were prepared by reacting 2-acetamido-4-methyl- and 2-acetamidothiazoles with formaldehyde and various secondary amines. The Mannich reaction of 2-acetamido-4-methylthiazole is completed in a short time by mixing the reactants, without the use of a solvent, but that of 2-acetamidothiazole requires heating of 1-2 hours in a water bath. Alkylation of triethoxycarbonylmethane with 2-acetamido-4-methyl-5-morpholinomethylthiazole thereby obtained afforded 2-acetamido-4-methyl-5-(2-triethoxycarbonylethyl) thiazole of m.p. 107°, whose hydrolysis gave 2-amino-4-methyl-5-thiazolepropionic acid, m.p. 257°, in a good yield. The latter was identified by admixture with the substance of m.p. 257° obtained by the condensation of ethyl 4-acetylbutyrate and thiourea.