Formic Acid → 5-Bromo-6-chloro-3-pyridinecarboxaldehyde

Participants

Reaction Steps

3-Bromo-2-chloro-5-cyanopyridine (8.6 g) in 90% formic acid (40 ml) and water (10 ml) were treated with Raney nickel/aluminium alloy (8.0 g) and the mixture stirred and heated to 55°-60° for 6 hours. The mixture was left to stand for two days, and then filtered. The filtrate was diluted to 500 ml with water and extracted with ether (2×250 ml). The ether extract was washed with aqueous sodium carbonate, dried, and evaporated to give an oil. The oil was diluted with toluene which was then removed under reduced pressure. The residue was diluted with a little ether, the solution filtered, and the filtrate evaporated to give an oil identified as the required aldehyde.

Provenance & Evidence