Synthesis of 4‐¹³C and 3,5‐¹³C labeled aniline as precursor of ¹³C ‐ labeled monosubstituted benzenes

Abstract

Abstract Aniline (IV), specifically 13 C labeled in the 4‐ or in the 3,5‐position (IVa and IVb), has been synthesized with 55% yield from 13 C labeled p‐nitrophenol (II). The reduction of the NO 2 group and the removal of the OH group was performed in one step by reduction and hydrogenolytic cleavage of p‐nitrophenol‐methanesulfonate (III), prepared in 90% yield from (II). From (IV) a number of specifically 13 C labeled monosubstituted benzenes C 6 H 5 Y (Y = CN, Hal, NO 2 ) are easily accessible.