| abstract |
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-. |