Trifluoroacetic acid → 2-Amino-3-(1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl ester

HRID 1177730Notes

Reaction equation

HRID 1177730 reaction equation
[CH3:1][O:2][C:3](=[O:30])[CH:4]([N:15](C(OC(C)(C)C)=O)C(OC(C)(C)C)=O)[CH2:5][N:6]1[CH2:11][CH2:10][C:9]2[NH:12][N:13]=[CH:14][C:8]=2[CH2:7]1.FC(F)(F)C(O)=O>C(Cl)Cl>[CH3:1][O:2][C:3](=[O:30])[CH:4]([NH2:15])[CH2:5][N:6]1[CH2:11][CH2:10][C:9]2[NH:12][N:13]=[CH:14][C:8]=2[CH2:7]1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 588643312-(Di-tert-butoxycarbonylamino)-3-(1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl ester

Product 1

HCID 588644802-Amino-3-(1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl esterYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-(di-tert-butoxycarbonylamino)-3-(1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl ester (0.55 g, 1 equiv.) in methylene chloride (5 mL, 0° C.) was added trifluoroacetic acid (1.5 mL). The ice bath was removed and stirring continued for 2 h. The solution was concentrated, redissolved in methanol, and passed onto a column of strong cation exchange resin. After flushing with methanol, the product was removed from the column by eluting with 2 M ammonia in methanol to afford the product as its free base (275 mg, 95%). 1H-NMR (CDCl3, 500 MHz) δ 2.71 (dd, J=12.8, 8.6, 1H), 2.74-2.91 (m, 6H), 3.48 (s, 2H), 3.54 (d, J=13.4, 1H), 3.62 (d, J=13.4, 1H), 3.69 (dd, J=8.2, 4.9, 1H), 3.73 (s, 3H), 7.27 (s, 1H). Mass spec.: 225.16 (MH)+.

Workup

  1. customThe ice bath was removed
  2. concentrationThe solution was concentrated
  3. dissolutionredissolved in methanol
  4. customAfter flushing with methanol
  5. customthe product was removed from the column
  6. washby eluting with 2 M ammonia in methanol

Sources & evidence

ORD record
ord-f6e441f52fe541bfbab4029ac5828018
Source dataset
uspto-grants-2010_11
Patent number
US07842808B2

Reaction notes

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