Improvement of Synthesis of L - Alanine Benzyl Ester p - Toluenesulfonate
Tang Linsheng Yin Yanbai Wen Shenglei Wang Jintian (College of Chemical Engineering, Qingdao Science and Technology University, Qingdao 266042)
Synthesis of L - alanine benzyl ester p - toluenesulfonate using L - alanine and benzyl alcohol as raw materials, p - toluenesulfonic acid as catalyst was studied with an emphasis on the choice of solvents for crystalization. The optimum synthetic conditions were as follows: n ( L - alanine ):n (benzyl alcohol):n ( p - toluenesulfonic acid) = 1.0:3.0:1.1, reaction temperature about 85℃, reaction time 6 - 7 h. The optimum solvent for crystalization was ethyl acetate. Under these conditions, the yield of the product was 89.47% with m.p. 109 -111℃, [a] = -6.1°(c=2,H2O).