Formaldehyde → 4-Chloro-2-hydroxybenzaldehyde

Temperatur

80 °C

A 2M solution of ethylmagnesium bromide in tetrahydrofuran (50 ml, 0.10 mole) was placed in a flask, and a solution of 12.85 g (0.10 mole) of 3-chlorophenol in 50 mL of diethyl ether was added slowly with stirring. The addition required two hours, after which the solvents were removed by evaporation under reduced pressure. Toluene (200 ml), 7.50 g (0.25 mole) of paraformaldehyde, and 17.92 g (0.10 mole) of hexamethylphosphoramide were added to the residue, and this mixture was heated at 80° C. for approximately 16 hours. The solvent was evaporated under reduced pressure, leaving a residue. This residue was washed successively with 50 mL of hydrochloric acid and 300 mL of water. Vacuum distillation of the washed residue yielded 11.50 g of 4-chlorosalicylaldehyde, b.p. 112° C. at 9 mm of Hg. This reaction was repeated several times.

1. additionThe addition required two hours
2. customafter which the solvents were removed by evaporation under reduced pressure
3. customThe solvent was evaporated under reduced pressure
4. customleaving a residue
5. washThis residue was washed successively with 50 mL of hydrochloric acid and 300 mL of water
6. distillationVacuum distillation of the washed residue

ORD-Eintrag

ord-e8df0bebc4294be48db9951d1906c2d9

Quelldatensatz

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05262390