Water → 3-chloro-5-fluoro-2-hydroxybenzaldehyde

Sodium hydroxide (50 g.) was dissolved in 70 ml. of water. 2-Chloro-4-fluorophenol (10 g., 0.068 mole) was added and then chloroform (30 ml.) The mixture was refluxed for two hours. Addition of chloroform (30 ml.) and reflux for 2 hours was twice repeated. The reaction mixture was cooled to room temperature and crude product recovered as the sodium salt by filtration. The crude was taken into water and acidified with 1N hydrochloric acid to yield product (6.6 g.) in the free phenolic form. The latter was chromatographed on 200 g. of silica gel, with 1:1 methylene chloride:hexane as eluant. The column was monitored by tlc. Clean product containing fractions were combined and evaporated to dryness to yield purified 3-chloro-5-fluoro-2-hydroxybenzaldehyde [3.08 g.; m.p. 81°-83° C., Rf 0.49 (1:1 methylene chloride:hexane); ir (CH2Cl2) 1658, 1460, 1439, 1289, 1230, 1116 cm-1 ].

1. temperaturereflux for 2 hours
2. filtrationcrude product recovered as the sodium salt by filtration
3. customto yield product (6.6 g.) in the free phenolic form
4. customThe latter was chromatographed on 200 g
5. additioncontaining fractions
6. customevaporated to dryness
7. customto yield
8. custompurified 3-chloro-5-fluoro-2-hydroxybenzaldehyde [3.08 g.; m.p. 81°-83° C., Rf 0.49 (1:1 methylene chloride:hexane); ir (CH2Cl2) 1658, 1460, 1439, 1289, 1230, 1116 cm-1 ]

ORD record

ord-9d298f939a934232929732b43f410038

Source dataset

uspto-grants-1984_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04448971