Methanol → Methyl 1H-indole-2-carboxylate

To 300 ml of a methanol solution of 30.0 g (186.2 mmol) of 2-indolecarboxylic acid was dropwise added 44.3 g (372.3 mmol) of thionyl chloride at 0° C. The reaction mixture was refluxed for 2 hours and the solvent was then distilled off under reduced pressure. Ice water was poured onto the resulting residue. The mixture was made basic by the addition of concentrated ammonium hydroxide. The mixture was extracted three times with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure to give 32.34 g (99.2%) of methyl 2-indolecarboxylate.

1. customat 0° C
2. temperatureThe reaction mixture was refluxed for 2 hours
3. distillationthe solvent was then distilled off under reduced pressure
4. additionIce water was poured onto the resulting residue
5. additionThe mixture was made basic by the addition of concentrated ammonium hydroxide
6. extractionThe mixture was extracted three times with ethyl acetate
7. washThe extract was washed with water
8. dry with materialdried over anhydrous magnesium sulfate
9. distillationThe solvent was then distilled off under reduced pressure

ORD record

ord-26edda41d5f448f190b525771ee681d0

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06248772B1