Expeditious One-Pot, Four-Step Preparation of 2-t-Butoxycarbonyl-6-hydroxy-1,2,3,4-tetrahydroisoquinoline and an Improved Conversion to Its 6-Cyano Derivative

Abstract

3-Methoxy-phenethylamine was subjected to a sequential imination/Pictet–Spengler/demethylation/Boc protection sequence that allowed a one-pot preparation of N-Boc-6-hydroxy-1,2,3,4-tetrahydroisoquinoline 1. This intermediate was elaborated almost quantitatively via an improved triflation/cyanation procedure to its 6-cyano analog 2.

Keywords:

• Cyanation
• one-pot
• Pictet–Spengler
• tetrahydroisoquinoline
• triflation