反应详情

In 15 ml of methanol is dissolved 300 mg of methyl 22-(2-hydroxy-3,4-dimethoxy-6-methylphenyl)docosanoate followed by addition of 20 ml of a 14% aqueous solution of sodium hydroxide. The mixture is stirred at 50°-60° C. for 1.5 hours. The reaction mixture is made acidic with 3N--HCl and extracted with ethyl acetate. The extract is washed with water and, after drying, the solvent is distilled off under reduced pressure. The residue is recrystallized from methanol to obtain 22-(2-hydroxy-3,4-dimethoxy-6-methylphenyl)docosanoic acid (IV:n=21), m.p. 67° C.-68° C. NMR(δ, in deuteriochloroform): 1.27(38H,b,CH2), 2.24(3H,s,nuclear CH3), 2.28-2.56(4H,m,CH2COO, nuclear CH2), 3.80(3H,s,OCH3), 3.84(3H,s,OCH3), 6.24(1H,s, nuclear H)

1. extractionHCl and extracted with ethyl acetate
2. washThe extract is washed with water
3. customafter drying
4. distillationthe solvent is distilled off under reduced pressure
5. customThe residue is recrystallized from methanol