Indoline-2-carboxylic acid → 2,3-dihydro-1H-indol-2-ylmethanol

Participants

Reaction Steps

Racemic 2,3-dihydro-1H-indole-2-carboxylic acid (5.0 g, 30.6 mmol) was suspended in methanol (50 ml). Sodium methoxide (1.66 g, 30.6 mmol) was added, and the resulting slurry was stirred several minutes before the solvent was removed in vacuo. The entire sample was suspended in anhydrous tetrahydrofuran (60 ml). Lithium aluminum hydride (1.0M solution in tetrahydrofuran; 30.6 ml, 30.6 mmol) was added dropwise over 15 minutes. The reaction mixture was refluxed for 3 hours. The ice-bath-chilled mixture was then cautiously quenched by dropwise addition of 15 percent aqueous sodium hydroxide (4 ml). The reaction was filtered, and the filtrate was concentrated in vacuo to afford (+)-2-hydroxymethyl-indoline (3.69 g) as a viscous brown oil, used in the next step without further purification. TLC Rf (silica gel plates; u.v. detection, elution with ethyl acetate/hexane=1:4 in volume): 0.15.

Provenance & Evidence