m-Chloroperbenzoic acid → 2-Chloro-4-methoxybenzene-1,3-diol

Into a reaction flask was introduced 2 g of 2-chloro-3-hydroxy-4-methoxybenzaldehyde in 50 ml methylene dichloride with an excess of m-chloroperbenzoic acid and the reaction refluxed for 2.5 hrs. After removal of the solvent, the solid residue was dissolved in 10 ml methanol and stirred with approximately 10 weight percent aqueous sodium hydroxide (10 ml) for 1 hr. After acidification to pH 1 with dilute HCl, the solution was filtered and the precipitate washed with 10 ml of cold water. The combined filtrate and wash was extracted with ether, the ether washed with 5% NaHCO3 (2×10 ml) and saturated NaCl solution (1×10 ml) and then evaporated to leave a solid which was crystallized from ethyl acetate-hexane mixture to provide the product as white silky needles (1.35 g). mp 69°-70°.

1. temperaturethe reaction refluxed for 2.5 hrs
2. customAfter removal of the solvent
3. dissolutionthe solid residue was dissolved in 10 ml methanol
4. filtrationAfter acidification to pH 1 with dilute HCl, the solution was filtered
5. washthe precipitate washed with 10 ml of cold water
6. washThe combined filtrate and wash
7. extractionwas extracted with ether
8. washthe ether washed with 5% NaHCO3 (2×10 ml) and saturated NaCl solution (1×10 ml)
9. customevaporated
10. customto leave a solid which
11. customwas crystallized from ethyl acetate-hexane mixture

ORD record

ord-5609809ae6ec4527911bb41bc4ee91c3

Source dataset

uspto-grants-1982_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04318846