Hydrochloric Acid → 1H-Pyrrolo[2,3-b]pyridine-4-carbaldehyde

Temperature

-78 °C

To a solution of (200 mg, 1.4 mmol) of 1H-Pyrrolo[2,3-b]pyridine-4-carbonitrile in THF (7 mL) at −78° C. under nitrogen was added Dibal-H (1.0 M in toluene, 3.07 mL, 3.07 mmol). The reaction mixture was stirred at −78° C. for 1 hr, warmed to 55° C. and stirred for additional 2 hr. One additional equivalent of DIBAL-H (1.4 mL, 1.4 mmol) was added and the mixture stirred at 55° C. for 2 hr. The mixture was cooled to 5° C., acidified with 2 M HCl and stirred for 15 min. The mixture was then neutralized with saturated NaHCO3 (aq), extracted with CH2Cl2 (5×25 mL), washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give 1H-Pyrrolo[2,3-b]pyridine-4-carboxaldehyde (107 mg, 52%). MS (ES+): 146 [MH+]. 1H NMR (DMSO-d6, 400 MHz): δ 7.22 (d, 1H, J=3.6 Hz), 7.57 (d, 1H, J=4.8 Hz), 7.67 (d, 1H, J=2.4 Hz), 8.61 (d, 1H, J=5.2 Hz), 10.42 (s, 1H).

1. temperaturewarmed to 55° C.
2. stirringstirred for additional 2 hr
3. stirringthe mixture stirred at 55° C. for 2 hr
4. temperatureThe mixture was cooled to 5° C.
5. stirringstirred for 15 min
6. extractionextracted with CH2Cl2 (5×25 mL)
7. washwashed with brine
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationconcentrated in vacuo

ORD record

ord-83bffc2d0a1046e09f4d27f532478116

Source dataset

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06949563B2