5-Boc-1,4,6,7-tetrahydropyrazolo[4,3-C]pyridine → 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

HRID 1353556Notes

Reaction equation

HRID 1353556 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][C:11]2[NH:14][N:15]=[CH:16][C:10]=2[CH2:9]1)=O)(C)(C)C>FC(F)(F)C(O)=O.O>[NH:14]1[C:11]2[CH2:12][CH2:13][NH:8][CH2:9][C:10]=2[CH:16]=[N:15]1

Participants

4

Reactant 1

HCID 103986805-Boc-1,4,6,7-tetrahydropyrazolo[4,3-C]pyridine

Product 1

HCID 27605834,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6422Trifluoroacetic acidSolvent

Procedure

1,4,6,7-Tetrahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester (0.70 g, 3.1 mmol) was dissolved in trifluoroacetic acid (10 mL) at 0° C., stirred for 1 h, and was concentrated. The residue was dissolved in ethanol and treated with concentrated hydrochloric acid (1 mL). The bis-hydrochloride salt precipitated out as a white solid which was filtered to give 510 mg (83%). The free base was prepared as needed by dissolving the salt in water, loading it onto an SCX column, flushing with methanol, and then eluting with 2 M ammonia in methanol.

Workup

  1. concentrationwas concentrated
  2. dissolutionThe residue was dissolved in ethanol
  3. additiontreated with concentrated hydrochloric acid (1 mL)
  4. customThe bis-hydrochloride salt precipitated out as a white solid which
  5. filtrationwas filtered
  6. customto give 510 mg (83%)
  7. customThe free base was prepared
  8. customflushing with methanol
  9. washeluting with 2 M ammonia in methanol

Sources & evidence

ORD record
ord-9b2970d0d1ab462289be402840caff85
Source dataset
uspto-grants-2007_05
Patent number
US07220862B2

Reaction notes

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