Hydrochloric Acid → HCID 9840634, compound

Temperature

100 °C

2,4-Dihydroxybenzoic acid (48.0 g), anhydrous potassium carbonate (21.5 g), benzyl chloride (39.4 g) and dry sulpholane (400 ml) were heated together, with stirring, at 100° C. for 20 hours. The mixture was then poured into water (2 liters), the resulting oil was separated and the aqueous layer extracted with diethyl ether (300 ml). The ether extract was evaporated and its residue was combined with the said oil layer and washed with water (500 ml) to remove sulpholane, and then was washed with brine, the aqueous washings were extracted with diethyl ether (400 ml), and the combined oil and ether extract were dried and evaporated to give crude benzyl 2,4-dihydroxybenzoate (64 g), m.p. 83°-88° C. This ester (20 g) was treated with anhydrous potassium carbonate (17.0 g) and benzyl chloride (22.8 g) in dry sulpholane (300 ml) and the mixture was stirred and heated at 140° C. for 3 hours. It was allowed to cool and was then poured into water (1500 ml) and the mixture was neutralised to pH 7 by treatment with hydrochloric acid. The precipitated crude benzyl 2,4-dibenzyloxybenzoate was heated at reflux with a mixture of aqueous sodium hydroxide solution (2N; 400 ml) and ethanol (50 ml) for 10 hours. The solution was allowed to cool, and was then diluted with a large volume of water and acidified to pH 1 by treatment with hydrochloric acid (2N) to give a white solid which was filtered off and recrystallized from ethanol to give 2,4-dibenzyloxybenzoic acid (16.8 g), m.p. 126°-128° C.

1. customthe resulting oil was separated
2. extractionthe aqueous layer extracted with diethyl ether (300 ml)
3. extractionThe ether extract
4. customwas evaporated
5. washwashed with water (500 ml)
6. customto remove sulpholane
7. washwas washed with brine
8. extractionthe aqueous washings were extracted with diethyl ether (400 ml)
9. extractionthe combined oil and ether extract
10. customwere dried
11. customevaporated
12. customto give crude benzyl 2,4-dihydroxybenzoate (64 g), m.p. 83°-88° C
13. stirringthe mixture was stirred
14. temperatureheated at 140° C. for 3 hours
15. temperatureto cool
16. customThe precipitated crude benzyl 2,4-dibenzyloxybenzoate
17. temperaturewas heated
18. temperatureat reflux with a mixture of aqueous sodium hydroxide solution (2N; 400 ml) and ethanol (50 ml) for 10 hours
19. temperatureto cool
20. additionwas then diluted with a large volume of water
21. customto give a white solid which
22. filtrationwas filtered off
23. customrecrystallized from ethanol

ORD record

ord-a7b304f19477446b9e4c99a4980e4880

Source dataset

uspto-grants-1979_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04146631