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

Methyl 4-hydroxybenzoate (1.52 g) is dissolved in trifluoroacetic acid (20 ml), and thereto is added hexamethylenetetramine (700 mg). The mixture is heated under reflux for 2 hours. The reaction solution is concentrated under reduced pressure, and thereto is poured ice-water. The mixture is then extracted with ethyl acetate. The organic layer is washed with a saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over sodium sulfate and evaporated to remove the solvent under reduced pressure. The resulting residue is dissolved in chloroform, and filtered to remove the insoluble materials. The filtrate is concentrated under reduced pressure, and purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1) to give the title compound (540 mg). ESI-MS M/Z:179[M−H]−

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 then extracted with ethyl acetate
6. washThe organic layer is washed with a saturated aqueous sodium hydrogen carbonate solution and saturated brine
7. dry with materialdried over sodium sulfate
8. customevaporated
9. customto remove the solvent under reduced pressure
10. dissolutionThe resulting residue is dissolved in chloroform
11. filtrationfiltered
12. customto remove the insoluble materials
13. concentrationThe filtrate is concentrated under reduced pressure
14. custompurified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=4/1)

ORD record

ord-45df273a44824923b1304039d5e52b81

Source dataset

uspto-grants-2009_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07605158B2