Potassium Carbonate → 1-(4-t-Butoxycarbonyl-benzyl)-5-propyl-1H-pyrazole-3-carboxylic acid ethyl ester

HRID 883502Notes

Reaction equation

HRID 883502 reaction equation
[C:1]([O:5][C:6](=[O:15])[C:7]1[CH:12]=[CH:11][C:10]([CH2:13]Br)=[CH:9][CH:8]=1)([CH3:4])([CH3:3])[CH3:2].[CH2:16]([O:18][C:19]([C:21]1[CH:25]=[C:24]([CH2:26][CH2:27][CH3:28])[NH:23][N:22]=1)=[O:20])[CH3:17].C(=O)([O-])[O-].[K+].[K+].[Li+].[Cl-]>CN(C=O)C>[CH2:16]([O:18][C:19]([C:21]1[CH:25]=[C:24]([CH2:26][CH2:27][CH3:28])[N:23]([CH2:13][C:10]2[CH:11]=[CH:12][C:7]([C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:15])=[CH:8][CH:9]=2)[N:22]=1)=[O:20])[CH3:17]

Participants

6

Reactant 4

HCID 11430Potassium CarbonateHCID 433294Lithium ChlorideHCID 7365260ethyl 3-propyl-1H-pyrazole-5-carboxylateHCID 11414578Tert-butyl 4-(bromomethyl)benzoate

Product 1

HCID 598309141-(4-t-Butoxycarbonyl-benzyl)-5-propyl-1H-pyrazole-3-carboxylic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To the recovered intermediate (19a) (1.4 g, 5 mmol, 1.0 eq) dissolved into 15 mL DMF, was added 5-propyl-1H-pyrazole-3-carboxylic acid ethyl ester (910 mg, 5.0 mmol, 1.0 eq) and potassium carbonate (0.8 g, 5.5 mmol, 1.1 eq) and the mixture was stirred at room temperature for 16 hours. The mixture was then added to 50 mL of 10% aq. LiCl solution and extracted with 50 mL EtOAc. The organic was dried over MgSO4, and concentrated under reduced pressure to yield intermediate (19b) and its regioisomer in a 1:1 ratio. The recovered regioisomers were dissolved into 25 mL MeOH. To this was added 10 mL of 1M NaOH and the mixture was stirred at room temperature over night. The mixture was acidified with acetic acid and concentrated under reduced pressure. The recovered oil was purified by preparatory HPLC, producing the desired regioisomer of the title compound as a white solid TFA salt after lyophilization (230 mg). 1H NMR (DMSO) 0.89 (t, 3H), 1.52 (s, 9H), 5.71 (s, 2H), 6.71 (s, 1H), 7.15 (d, 2H), 7.83 (d, 2H), 13.28 (br s, 1H).

Workup

  1. extractionextracted with 50 mL EtOAc
  2. dry with materialThe organic was dried over MgSO4
  3. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-8ea6e6c1321048a3a5d61545d3f3f9f3
Source dataset
uspto-grants-2012_08
Patent number
US08236846B2

Reaction notes

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