Hydrate;dihydrochloride → O-Methyl-L-Tyrosine

A suspension of dihydrochloride monohydrate of FR-48736 substance [1-(6-amino-9H-purin-9-yl)-1,3-dideoxy-3-(O-methyl-L-tyrosylamino)-β-D-ribofuranuronic acid dihydrochloride monohydrate] (300 mg) prepared by Example 98 in 6N hydrochloric acid (20 ml) was refluxed for 12 hours. The resulting solution was cooled and the solvent was evaporated under reduced pressure. The residue was dissolved in water (30 ml) and the solution was adjusted to pH 7 with 1N sodium hydroxide. Then, the solution was applied to a column of Diaion HP 20 (200 ml). The column was washed with water (400 ml) and eluted with a mixture of methanol and water (3:7, 200 ml). The solvent was evaporated under reduced pressure. The residue was chromatographed on a cellulose column and eluted with a mixture of acetonitrile and water (8:2). The fractions containing the object compound were combined and the solvent was evaporated under reduced pressure to give O-methyl-L-tyrosine (30 mg).