US EPA

1551631 

Journal Article 

Nitration Under Continuous Flow Conditions: Convenient Synthesis of 2-Isopropoxy-5-nitrobenzaldehyde, an Important Building Block in the Preparation of Nitro-Substituted Hoveyda-Grubbs Metathesis Catalyst 

Knapkiewicz, P; Skowerski, K; Jaskolska, DE; Barbasiewicz, M; Olszewski, TK 

2012 

1 

Organic Process Research and Development
ISSN: 1083-6160 

16 

8 

1430-1435 

10.1021/op300116j 

WOS:000307527000014 

Herein, we describe the use of continuous flow chemistry
for selective, efficient and reproducible nitration of 2-isopropoxybenzaldehyde to produce the
desired 2-isopropoxy-5-nitrobenzaldehyde, an important building block in the preparation of a
ligand of nitro-substituted Hoveyda-Grubbs metathesis catalyst. Nitration was done with red
fuming HNO3, and this challenging and hazardous process was performed using a flow-through
silicon-glass microreactor equipped with a set of temperature sensors, and with a productivity of
13 g/h, providing us with a reproducible chemical process amenable for production of sufficient
quantities of 2-isopropoxy-5-nitrobenzaldehyde for ongoing large-scale synthesis of nitro-
substituted Hoveyda-Grubbs metathesis catalyst.