The present invention provides a safer method for production of a cis-4-fluoro-L-proline derivative under milder conditions and in good yield to give a product of high purity on an industrial scale at low cost. Namely, the present invention provides a method for producing a cis-4-fluoro-L-proline derivative, which comprises reacting a trans-4-hydroxy-L-proline derivative of the following Formula [I]:
(wherein R
1
represents a protecting group for an α-amino group, and R
2
represents a protecting group for a carboxyl group) with N,N-diethyl-N-(1,1,2,3,3,3-hexafluoropropyl)amine in the presence of a hydrogen fluoride-scavenger.
本发明提供了一种更安全的方法,在较温和的条件下并且高产率地生产cis-4-
氟-
L-脯氨酸衍
生物,以在工业规模下低成本地得到高纯度的产物。即,本发明提供了一种制备cis-4-
氟-
L-脯氨酸衍
生物的方法,该方法包括将以下式[I]的trans-
4-羟基-
L-脯氨酸衍
生物(其中R1表示α-
氨基保护基,R2表示羧基保护基)与N,N-二乙基-N-(1,1,2,3,3,3-六
氟丙基)胺在
氢氟酸清除剂的存在下反应。