Réaction #2666

Équation de réaction

5-nitro vanillin

boron tribromide

→

expected product

Rendement 55.4%

3-nitro-4,5-dihydroxy benzaldehyde

Rendement 55.4%

Solvants

dichloromethane

dichloromethane

Conditions de réaction

Traitement

1. 1
   Concentrationwas concentrated
2. 2
   workup.WAITleft for 16 hours at ambient temperature
3. 3
   ExtractionExtraction
4. 4
   Lavagethe organic phase was washed
5. 5
   Autredried
6. 6
   Concentrationconcentrated

Mode opératoire

35 g of 5-nitro vanillin (commercial) and 1200 ml of dichloromethane were mixed together under nitrogen and the mixture was cooled to 0° C. 533 ml of a molar solution of boron tribromide in dichloromethane were added and the mixture stood for 2 days at abmient temperature and then was concentrated. The residue was taken up cold (ice bath+methanol) in 300 ml of 2N hydrochloric acid and the mixture was stirred for two to three hours at this temperature, then left for 16 hours at ambient temperature. Extraction was carried out with ethyl acetate and the organic phase was washed, dried and concentrated to obtain 18 g of the expected product melting at >260° C.

Source