The objective of the present invention is to provide a tyrosine derivative which is useful as a melatonin MT
1
receptor antagonist, and a method for producing a specific tyrosine derivative with high yield by efficiently introducing an iodine atom at the para position of the phenolic hydroxy group in the benzene ring of tyrosine with good regioselectivity. The tyrosine derivative of the present invention is characterized in being represented by the following formula (I):
wherein R
1
is a protective group of the amino group and the like; R
2
is a protective group of the carboxy group and the like; R
3
is a hydrogen atom and the like; R
4
is a halogen atom and the like; A is —(CH
2
)
l
—[Z(CH
2
)
m
]
n
—; X is a leaving group.
本发明的目的是提供一种对苯
酪氨酸衍
生物,该衍
生物可用作
褪黑激素MT1受体拮抗剂,并通过在对
苯酚羟基的苯环中有效地引入
碘原子,以高产率生产具有良好区域选择性的特定对苯
酪氨酸衍
生物的方法。本发明的对苯
酪氨酸衍
生物的特征在于其由以下公式(I)表示:其中R1是
氨基的保护基等;R2是羧基的保护基等;R3是氢原子等;R4是卤原子等;A是—(
CH2)l—[Z( )m]n—;X是离去基团。