Dimethylformamide → 3-Bromo-5-hydroxybenzaldehyde

Temperature

-10 °C

To a toluene solution (1.6 M) of n-butyl lithium (2.5 M hexane solution, 2.1 eq.) was added at −10° C. n-butyl magnesium chloride (2.0 M THF solution, 0.6 eq.). The reaction mixture was stirred at −10° C. for 30 min before a toluene solution (0.7 M) of 3,5-dibromophenol (1 eq.) was added dropwise at −10° C. over a period of 35 min. After stirring at −10° C. for a further 30 min, the reaction mixture was cooled to −40° C. before DMF (20 eq.) was added dropwise over 20 min. The reaction mixture was then slowly warmed to rt and allowed to stir at rt for 1 h. The reaction was carefully quenched at 0° C. with 10% aqueous HCl and extracted with ether. The combined organic extracts were washed with water and brine and dried over MgSO4. Concentration of the filtrate in vacuo afforded a yellow solid. Recrystallization of the crude product in ether/hexane afforded the title compound as a beige powder.

1. additionwas added dropwise at −10° C. over a period of 35 min
2. additionwas added dropwise over 20 min
3. temperatureThe reaction mixture was then slowly warmed to rt
4. stirringto stir at rt for 1 h
5. customThe reaction was carefully quenched at 0° C. with 10% aqueous HCl
6. extractionextracted with ether
7. washThe combined organic extracts were washed with water and brine
8. dry with materialdried over MgSO4
9. customConcentration of the filtrate in vacuo afforded a yellow solid
10. customRecrystallization of the crude product in ether/hexane

ORD record

ord-48f99faaa61b475e87331e6159ab4996

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08076359B2