反应详情

Methylhesperidin is popularly known as a soluble vitamin P and a food additive, and is not injurious to the health. Methylhesperidin is produced by methylating hesperidin. The methylation of hesperidin is described in, for example, C. W. Wilson's U.S. Pat. No. 2,425,291(1947); I. Sakieki: Nippon Kagaku Zasshi 79, 733-736, 736-740 and 1103-1107(1958); Ibid, 80, 419-423, 423-426(1959), and; Japanese Patent Publication No. 23,091/1961 (see also Chem. Abstr., 54, 4557i and 5632f, 55, 5481e and 58, P6918d). The methylation may be effected, for example, as follows. Dimethyl sulfate is incorporated in an alkaline solution of hesperidin, and then, sulfuric acid is added thereto to adjust the pH of the reaction mixture to a value between 4 and 5. The reaction product is extracted with n-butyl alcohol and, after n-butyl alcohol is distilled off under reduced pressure, the residue is recrystallized from isopropanol thereby to obtain a yellow powder. The methylation of hesperidin may also be effected by using diazomethane or methyl iodide, instead of dimethyl sulfate, for example, as described in F. E. King and A. Robertson: J. Chem. Soc., 1931, P1704, and G. Zemplen and A. K. Tettamanti: Chem. Ber., 71, P2511(1938).