Tetrahydrofuran → Indole

To a solution of 1 (426 mg, 1.26 mmol) in TBF (6 mL) at −78° C. was added dropwise a 1.8 M solution of LDA in THF (1.54 mL, 2.78 mmol) and the reaction stirred for 1 hour, then pyruvonitrile (0.208 mL, 2.78 mmol) was added dropwise and the reaction was stirred for 15 minutes turning homogeneous. The reaction was quenched by the addition of satd. NH4Cl (10 mL), the layers separated, and the aqueous extracted with Et2O (3×10 mL). The combined organics were dried (MgSO4), filtered and concentrated in vacuo. The residue was purified on silica gel gradiently eluted with 20 to 40% EtOAc/hexanes to give 2 (230 mg, 48% yield) as an off-white solid. Rt=1.71 min using Phenomenex 30×4.6 5u column with flow rate of 5 mL/min over 2 min gradient. 0 to 100% B. Solvent A=10/90/0.1% MeOH/H2O/TFA. Solvent B=90/10/0.1%. [M+H]=380.

1. stirringthe reaction was stirred for 15 minutes
2. customThe reaction was quenched by the addition of satd
3. customNH4Cl (10 mL), the layers separated
4. extractionthe aqueous extracted with Et2O (3×10 mL)
5. dry with materialThe combined organics were dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was purified on silica gel
9. washgradiently eluted with 20 to 40% EtOAc/hexanes

ORD record

ord-8c3d7b36415547a8809216f3d744ec4f

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07772232B2