Hydrochloric Acid → Methyl 4-aminomethylsalicylate hydrochloride

Crude methyl 4-(azidomethyl)-2-hydroxybenzoate was dissolved in methanol (750 mL) in a 2 L Parr hydrogenation flask. Palladium on carbon catalyst (10% [w/w], 3.8 g) in water (25 mL) was added, followed by concentrated hydrochloric acid (35 mL). The flask was affixed to a Parr hydrogenator, and the mixture was shaken at room temperature under 40 psi of hydrogen for 16 hours. The reaction mixture was then filtered through a 0.45 mm nylon filter. The retained solid was then washed with methanol (150 mL), water (100 mL), and methanol again (150 mL). The combined filtrates were evaporated to dryness to afford a tan solid. This solid was dissolved in hot denatured ethanol (150 mL) and the solution was allowed to cool to room temperature. White crystals formed quickly. Finally, the mixture was then chilled for 16-18 hours at 4° C. to complete crystallization. The solid was filtered, washed with a little cold ethanol (50 mL) and then diethyl ether (150 mL), and dried in vacuo over potassium hydroxide pellets to afford 51.5 g (65% yield based on methyl 4-bromomethyl-2-hydroxybenzoate) of methyl 4-aminomethyl-2-hydroxybenzoate hydrochloride (m.p. 225-227° C., open capillary, uncorrected).

1. filtrationThe reaction mixture was then filtered through a 0.45 mm nylon
2. filtrationfilter
3. washThe retained solid was then washed with methanol (150 mL), water (100 mL), and methanol again (150 mL)
4. customThe combined filtrates were evaporated to dryness
5. customto afford a tan solid
6. customWhite crystals formed quickly
7. temperatureFinally, the mixture was then chilled for 16-18 hours at 4° C.
8. customcrystallization
9. filtrationThe solid was filtered
10. washwashed with a little cold ethanol (50 mL)
11. dry with materialdiethyl ether (150 mL), and dried in vacuo over potassium hydroxide pellets

ORD record

ord-9b1e4be2e349452e88a8ace59c577de3

Source dataset

uspto-grants-2000_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06156884