A Simple and Efficient Procedure for the Synthesis of Optically Active 4-Methoxy-α-Methylphenylethylamine from Tyrosine

Abstract

Optically active 4-methoxy-α-methylphenylethylamine (1), a useful chiral building block in medicinal chemistry, was synthesized from L- or D-tyrosine by using a simple and efficient procedure via one-pot zinc reduction of the corresponding O-tosylate (4) in the presence of H₂O and NaI in pure form.

^a)Present address: Zeria Pharmaceutical Co., Ltd., 2512—1, Oshikiri, Kohnan-machi, Ohsato-Gun, Saitama, 360—01, Japan

Notes

^a)Present address: Zeria Pharmaceutical Co., Ltd., 2512—1, Oshikiri, Kohnan-machi, Ohsato-Gun, Saitama, 360—01, Japan

We will soon submit the manuscript related to synthetic studies of TA-2005

The tosylation of (S)-3 by using an usual method (TsCl (1.2eq) / pyridine, 0°C, 1.5hr) gave the desired (S)-4 in lower yield (61.8 %) compared to this PTC method

The synthetic study for TXA₂ antagonists was reported by Kohno H. et al.; See Abstracts Papers of 15th Symposium on Med.Chem. (Osaka, Japan), 1994, pp. 151—152.