Trifluoroacetic acid → HCID 83872254, compound

HRID 523012Notes

Reaction equation

HRID 523012 reaction equation
[CH3:1][N:2]1[C:10]2[CH2:9][CH2:8][CH2:7][N:6](C(OC(C)(C)C)=O)[C:5]=2[CH:4]=[N:3]1.C(O)(C(F)(F)F)=O>C(Cl)Cl>[CH3:1][N:2]1[C:10]2[CH2:9][CH2:8][CH2:7][NH:6][C:5]=2[CH:4]=[N:3]1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 900409854H-Pyrazolo[4,3-b]pyridine-4-carboxylic acid, 1,5,6,7-tetrahydro-1-methyl-, 1,1-dimethylethyl ester

Product 1

HCID 83872254HCID 83872254, compoundYield 69.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of tert-butyl 1-methyl-6,7-dihydro-1H-pyrazolo[4,3-b]pyridine-4(5H)-carboxylate (55 mg, 232 μmol) in CH2Cl2 (4 mL) was added TFA (740 mg, 500 μL, 6.49 mmol). After 18 h, the reaction mixture was concentrated in vacuo and the residue obtained purified by chromatography (40 g column, 50 m silica-gel from Analogix, 0 to 5% 9:1 methanol:ammonium hydroxide in CH2Cl2, 20 min) to give 1-methyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-b]pyridine (22 mg, 69%). 1H NMR (CHLOROFORM-d) δ: 7.05 (s, 1H), 3.70 (s, 3H), 3.08-3.21 (m, 2H), 2.88 (br. s., 1H), 2.64 (t, J=6.4 Hz, 2H), 1.84-2.01 (m, 2H). MS (EI/CI) m/z: 138.2 [M+H]+.

Workup

  1. concentrationthe reaction mixture was concentrated in vacuo
  2. customthe residue obtained
  3. custompurified by chromatography (40 g column, 50 m silica-gel from Analogix, 0 to 5% 9:1 methanol:ammonium hydroxide in CH2Cl2, 20 min)

Sources & evidence

ORD record
ord-172b00524e844c1b9e5825d52fc33e83
Source dataset
uspto-grants-2016_05
Patent number
US09334278B2

Reaction notes

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