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 2355901Notes

Reaction equation

HRID 2355901 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

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-5dd5fefc08db4f6eb9d43bb1c14c2f1e
Source dataset
uspto-grants-2010_07
Patent number
US07754732B2

Reaction notes

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