反应详情

Crotonic aldehyde (33.0 mL, 0.40 mol) was added to 3-aminophenylacetic acid (30.0 g, 0.20 mmol) in concentrated hydrochloric acid (400 mL) and toluene (100 mL) at 110° C. The mixture was heated at 1100 for 90 minutes. The aqueous layer was separated, washed with diethyl ether (350 mL) then neutralised with aqueous ammonia. The aqueous solution was washed with chloroform (3×500 mL) and the organic phase was evaporated in vacuo. The solid residue was refluxed with chloroform (900 mL) and methanol (100 mL) then the solution was decanted and purified by column chromatography on silica gel (gradient of chloroform:MeOH 9:1 to 4:1) to afford a mixture of isomeric acids. This was purified by fractional crystallisation using isopropanol to afford the title compound as a white solid in 12% yield, 4.90 g.

1. temperatureThe mixture was heated at 1100 for 90 minutes
2. customThe aqueous layer was separated
3. washwashed with diethyl ether (350 mL)
4. washThe aqueous solution was washed with chloroform (3×500 mL)
5. customthe organic phase was evaporated in vacuo
6. temperatureThe solid residue was refluxed with chloroform (900 mL) and methanol (100 mL)
7. customthe solution was decanted
8. custompurified by column chromatography on silica gel (gradient of chloroform:MeOH 9:1 to 4:1)
9. customto afford
10. additiona mixture of isomeric acids
11. customThis was purified by fractional crystallisation