反应详情

温度

22 °C

6-Methylindole (2.785 g, 21.2 mmol) in dry Et2O (30 mL) was chilled to 0° C. and a solution of ZnBH4 in Et2O (~1.5 eq.; 215 mL of 0.15M) was added. The mixture was stirred 3 days at 22° C. in darkness and then quenched by addition of 1M aqueous HCl (until no further H2(g) evolved on mixing) followed by basification to pH >10 with 2N NaOH. The ether phase was separated and washed with brine, tided over MgSO4(s), filtered, and concentrated in vacuo to afford >90% pure 6-methyl-indoline as a syrup (2.82 g; GC/MS: RT=0.63 min., M+ =133). This material can be purified by chromatography on silica (25% EtOAc/hexanes) or vacuum distillation but was typically used without further purification. The following indolines were prepared in an analogous manner from the appropriately substituted indoles:

1. customquenched by addition of 1M aqueous HCl (until no further H2(g)
2. additionon mixing)
3. customThe ether phase was separated
4. washwashed with brine
5. filtrationfiltered
6. concentrationconcentrated in vacuo