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

HRID 2250213Notes

Reaction equation

HRID 2250213 reaction equation
[CH3:1][O:2][C:3](=[O:32])[CH:4]([N:17](C(OC(C)(C)C)=O)C(OC(C)(C)C)=O)[CH2:5][N:6]1[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[NH:14][N:15]=[CH:16][C:8]=2[CH2:7]1.FC(F)(F)C(O)=O>C(Cl)Cl>[CH3:1][O:2][C:3](=[O:32])[CH:4]([NH2:17])[CH2:5][N:6]1[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[NH:14][N:15]=[CH:16][C:8]=2[CH2:7]1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 588644042-(Di-tert-butoxycarbonylamino)-3-(7,7-dimethyl-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl ester

Product 1

HCID 588644942-Amino-3-(7,7-dimethyl-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl esterYield 94%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-(di-tert-butoxycarbonylamino)-3-(7,7-dimethyl-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-5-yl)-propionic acid methyl ester (0.49 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 loaded onto a column of strong cation exchange resin. After flushing with methanol, the product was removed from the column by eluting with 2M ammonia in methanol to afford the product as its free base (250 mg, 94%). 1H-NMR (CDCl3, 500 MHz) δ 1.27 (s, 3H), 1.28 (s, 3H), 2.41 (d, J=11.3, 1H), 2.50 (d, J=11.3, 1H), 2.69 (dd, J=12.5, 7.9, 1H), 2.82 (dd, J=12.5, 5.2, 1H), 3.45 (d, J=12.8, 1H), 3.52 (d, J=12.8, 1H), 3.67 (m, 1H), 3.69 (s, 3H), 7.19 (s, 1H). Mass spec.: 253.16 (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 2M ammonia in methanol

Sources & evidence

ORD record
ord-0b06715ac0cc40d3991552e6aa9e1f24
Source dataset
uspto-grants-2008_01
Patent number
US07314883B2

Reaction notes

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