| 摘要 |
PROBLEM TO BE SOLVED: To readily produce the subject high-purity compound useful as a raw material for medicines such as an antimicrobial agent, an antiviral agent or the like by reacting a specific nitrile compound with urea and separating an aqueous layer from the resultant reactional mixture liquid. SOLUTION: At least one nitrile compound selected from the group consisting of a 3-alkoxyacrylonitrile represented by formula I (R<1> is a 1-6C alkyl) and a 3,3-dialkoxypropionitrile represented by formula II (R<2> and R<3> are each a 1-6C alkyl) is reacted with urea in the presence of an alkali metallic alcoholate represented by formula III (R<4> is a 1-6C alkyl; X is an alkali metal) in a sparingly water-soluble organic solvent to produce an alkali metallic salt of cytosine represented by formula IV. Water is then added and mixed with the resultant reactional mixture liquid containing the alkali metallic salt to thereby separate the reactional mixture liquid into layers of an aqueous layer and an organic solvent layer. A water-soluble lower alcohol is further added to the separated aqueous layer containing the alkali metallic salt and the prepared aqueous solution is then neutralized with an acid to thereby deposit and isolate the objective cytosine crystal. |
