o ‐Nitrobenzaldehyde

Abstract

o ‐Nitrobenzaldehyde intermediate: o ‐nitrobenzylpyridinium bromide intermediate: N‐( p ‐dimethylaminophenyl)‐α‐( o ‐nitrophenyl)nitrone product: o ‐nitrobenzaldehyde product: fluoro‐o‐nitrobenzaldehydes reactant: Fluoro‐2‐nitrobenzylpyridinium Bromide intermediate: N‐(p‐dimethylaminophenyl)‐ α‐(fluoro‐o‐nitrophenyl)nitrone

Preparation of Tyrian Purple (6,6′-Dibromoindigo): Past and Present

“…An application of the Kröhnke method by Clarke [ 65 ] gave several substituted o -nitrobenzaldehydes in high overall yields from the respective toluenes. This application has served for a Organic Synthesis procedure by Kalir [ 66 ] for the preparation of o -nitrobenzaldehyde ( 16 ) in a 47-53% overall yield, and as the basis of a synthesis of 8 by Danieli and coworkers [ 67 ]. Cooksey [ 38 ] likewise reported a 55% overall yield of 8 using the Kröhnke procedure starting from 12 as part of his complete synthesis of 1 ( Scheme 7 ).…”