Hexamethylenetetramine → Benzoic acid, 3-formyl-4-hydroxy-, methyl ester

Methyl 4-hydroxybenzoate (1.52 g) is dissolved in trifluoroacetic acid (20 ml), thereto is added hexamethylenetetramine (700 mg) and the mixture is heated under reflux for 2 hours. The reaction solution is concentrated under reduced pressure, thereto is poured ice-water, and then the mixture is extracted with ethyl acetate. The organic layer is washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over sodium sulfate and the solvent is evaporated under reduced pressure. The resulting residue is dissolved in chloroform, and then filtered to remove the insoluble materials. The filtrate is concentrated under reduced pressure, and then purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1) to give the title compound (540 mg).

1. temperaturethe mixture is heated
2. temperatureunder reflux for 2 hours
3. concentrationThe reaction solution is concentrated under reduced pressure
4. additionis poured ice-water
5. extractionthe mixture is extracted with ethyl acetate
6. washThe organic layer is washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine
7. dry with materialdried over sodium sulfate
8. customthe solvent is evaporated under reduced pressure
9. dissolutionThe resulting residue is dissolved in chloroform
10. filtrationfiltered
11. customto remove the insoluble materials
12. concentrationThe filtrate is concentrated under reduced pressure
13. custompurified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1)

ORD record

ord-5128218e2d7f4b7aa514eb6caf918e90

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07531537B2