Sodium Carbonate → 1-Phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

tert-Butyl 3-((dimethylamino)methylene)-4-oxopiperidine-1-carboxylate (2.1 g, 8.3 mmol) was dissolved in MeOH (100 mL), and water (50 mL) was added followed by the addition of sodium carbonate (0.53 g, 5.0 mmol) and phenyl hydrazine hydrochloride (1.43 g, 9.9 mmol). Finally, acetic acid (1 mL) was added and the resulting reaction mixture was stirred at RT for 1 h. The reaction mixture was made basic by adding saturated aqueous sodium bicarbonate (ca. 20 mL) and the MeOH was removed under reduced pressure. The resulting reaction mixture was extracted with CH2Cl2 (3×40 mL) and the combined extracts were dried over anhydrous sodium sulfate, filtered, and concentrated to afford the crude product. Purification by flash chromatography on silica gel using 20% EtOAc in hexanes as the eluent afforded 1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine (1.63 g, 66%) as a yellow oil.

1. customthe resulting reaction mixture
2. customthe MeOH was removed under reduced pressure
3. customThe resulting reaction mixture
4. extractionwas extracted with CH2Cl2 (3×40 mL)
5. dry with materialthe combined extracts were dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customto afford the crude product
9. customPurification by flash chromatography on silica gel using 20% EtOAc in hexanes as the eluent

ORD record

ord-98f86ad785a442389aecb747f1332066

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09334269B2