Lithium borohydride → 1-(3-Hydroxy-propyl)-3-(4-trifluoromethyl-phenyl)-1,4,6,7-tetrahydropyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester

HRID 271772Notes

Reaction equation

HRID 271772 reaction equation
[Li+].[BH4-].[C:3]([O:7][C:8]([N:10]1[CH2:15][CH2:14][C:13]2[N:16]([CH2:29][CH2:30][C:31](OC)=[O:32])[N:17]=[C:18]([C:19]3[CH:24]=[CH:23][C:22]([C:25]([F:28])([F:27])[F:26])=[CH:21][CH:20]=3)[C:12]=2[CH2:11]1)=[O:9])([CH3:6])([CH3:5])[CH3:4]>C1COCC1>[C:3]([O:7][C:8]([N:10]1[CH2:15][CH2:14][C:13]2[N:16]([CH2:29][CH2:30][CH2:31][OH:32])[N:17]=[C:18]([C:19]3[CH:24]=[CH:23][C:22]([C:25]([F:28])([F:26])[F:27])=[CH:21][CH:20]=3)[C:12]=2[CH2:11]1)=[O:9])([CH3:6])([CH3:5])[CH3:4]

Participants

4

Procedure

A solution of LiBH4 (26 mg, 1.2 mmol) in THF (0.5 mL) was added to a 0° C. solution of 1-(2-methoxycarbonyl-ethyl)-3-(4-trifluoromethyl-phenyl)-1,4,6,7-tetrahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester (317 mg, 0.70 mmol) in THF (4.0 mL). The mixture was stirred for 5 min then additional LiBH4 (15 mg) was added and stirring continued for 17 h. The mixture was partitioned between EtOAc (80 mL) and saturated aqueous NaHCO3 (20 mL). The aqueous layer was extracted with EtOAc (2×20 mL). The combined extracts were dried over Na2SO4 and concentrated. Column chromatography (silica, 0-8% MeOH/CH2Cl2) afforded 268 mg (95%) of the title compound. HPLC (reverse phase conditions), tR=6.82 min. MS (electrospray): m/z calculated for C21H26F3N3O3 [M++Na] 448.18, found 448.10. 1H NMR (CDCl3, 400 MHz): 7.73 (br d, J=8.2 Hz, 2H), 7.65 (br s, 2H), 4.64 (br s, 2H), 4.21 (t, J =6.4 Hz, 2H), 3.76 (br s, 2H), 3.66 (t, J=5.7 Hz, 2H), 2.73 (br t, J=5.4 Hz, 2H), 2.04 (q, J=6.1, 2H), 1.48 (s, 9H).

Workup

  1. stirringstirring
  2. waitcontinued for 17 h
  3. customThe mixture was partitioned between EtOAc (80 mL) and saturated aqueous NaHCO3 (20 mL)
  4. extractionThe aqueous layer was extracted with EtOAc (2×20 mL)
  5. dry with materialThe combined extracts were dried over Na2SO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-3b76eee224994fed9ba2f6c1153110ef
Source dataset
uspto-grants-2008_11
Patent number
US07452890B2

Reaction notes

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