3-Hydroxybenzaldehyde → 2-Bromo-5-hydroxybenzaldehyde

Temperature

37.5 °C

3-Hydroxybenzaldehyde (120 g, 0.98 moles) was suspended in 2400 mL of CH2Cl2 in a 5 L 4-neck round bottom flask equipped with overhead stirrer, temperature probe, addition funnel, and condenser. The mixture was heated to 35-40° C. in order to dissolve the starting material. Bromine (52 mL, 1.0 moles, 1.02 eq.) was added dropwise through the addition funnel at a rate which maintained the reaction temperature between 35-38° C. The mixture was then allowed to stir overnight at 35° C. The mixture was slowly cooled to −5-0° C. over two hours and then allowed to stir at that temperature for 1 h more. The solid which formed was then collected by filtration through a Buchner funnel and the filter cake washed with 400 mL of a cold 1:1 CH2Cl2:heptane solution. The gray solid was then dried in vacuo (0.2 mm Hg) at room temperature. Yield=124.3 g (63%).

1. customequipped with overhead stirrer
2. additiontemperature probe, addition funnel, and condenser
3. dissolutionto dissolve the starting material
4. temperaturemaintained the reaction temperature between 35-38° C
5. temperatureThe mixture was slowly cooled to −5-0° C. over two hours
6. stirringto stir at that temperature for 1 h more
7. customThe solid which formed
8. filtrationwas then collected by filtration through a Buchner funnel
9. washthe filter cake washed with 400 mL of a cold 1:1 CH2Cl2
10. customThe gray solid was then dried in vacuo (0.2 mm Hg) at room temperature

ORD record

ord-6199255c2d7b41e7bba7aa4e416ade75

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07368566B2