A novel industrial process for producing a compound represented by general formula (I), or a salt thereof excellent in purity and yield, which comprises reacting a compound represented by general formula (II), or a salt thereof with a compound represented by R³-A-OH, a reactive derivative thereof or a salt thereof. In the above formulae, R² represents cyclo(lower)alkyl, aryl or aryl(lower)alkyl, each of which may be halogenated; R³ represents lower alkyl, aryl, aryl(lower)alkoxy or heterocycle, each of which may be halogenated; A represents - C(=O)-, -SO₂-or lower alkylene; and Y represents -C(=O)-, -SO₂- or -C(=O)-NH-.
                            一种生产通式(I)代表的化合物或其盐的纯度和收率极佳的新型工业工艺,该工艺包括将通式(II)代表的化合物或其盐与R³-A-OH代表的化合物、其反应衍
生物或其盐反应。在上式中,R²代表环(低级)烷基、芳基或芳基(低级)烷基,其中每个均可卤化;R³代表低级烷基、芳基、芳基(低级)烷氧基或杂环,其中每个均可卤化;A代表-C(=O)-、-SO₂-或低级亚烷基;Y代表-C(=O)-、-SO₂-或-C(=O)-NH-。