(2S,4R)-4-hydroxy-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acid → (2S,4R)-1-(tert-butoxycarbonyl)-4-((4-methoxyisoquinolin-1-yl)oxy)pyrrolidine-2-carboxylic acid

HRID 1852177Notes

Reaction equation

HRID 1852177 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][C@H:11]([OH:13])[CH2:10][C@H:9]1[C:14]([OH:16])=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2].Cl[C:18]1[C:27]2[C:22](=[CH:23][CH:24]=[CH:25][CH:26]=2)[C:21]([O:28][CH3:29])=[CH:20][N:19]=1.CC([O-])(C)C.[K+]>CS(C)=O>[C:1]([O:5][C:6]([N:8]1[CH2:12][C@H:11]([O:13][C:18]2[C:27]3[C:22](=[CH:23][CH:24]=[CH:25][CH:26]=3)[C:21]([O:28][CH3:29])=[CH:20][N:19]=2)[CH2:10][C@H:9]1[C:14]([OH:16])=[O:15])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 88804(2S,4R)-4-hydroxy-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acidHCID 222501441-Chloro-4-methoxyisoquinolineHCID 23665647Potassium tert-butoxide

Product 1

HCID 68401973(2S,4R)-1-(tert-butoxycarbonyl)-4-((4-methoxyisoquinolin-1-yl)oxy)pyrrolidine-2-carboxylic acidYield 71.8%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

To a solution of (2S,4R)-1-(tert-butoxycarbonyl)-4-hydroxypyrrolidine-2-carboxylic acid (2.0 g, 8.6 mmole) and 1-chloro-4-methoxyisoquinoline (2.0 g, 10.3 mmole) in DMSO (15 mL) was added t-BuOK (1 M solution in THF, 25.9 mL) at room temperature under nitrogen atmosphere. The reaction mixture was stirred at room temperature for 2 h. The reaction mass was quenched with aqueous citric acid solution and extracted with ethyl acetate (50 mL×3). The combined organics were washed with water, brine solution, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to get crude compound. The crude compound was purified by silica gel chromatography (55% ethyl acetate in pet-ether) to get 2.4 g (71.4%) of (2S,4R)-1-(tert-butoxycarbonyl)-4-((4-methoxyisoquinolin-1-yl)oxy)pyrrolidine-2-carboxylic acid as gummy liquid. 1H NMR (400 MHz, CD3OD): δ ppm 8.13-8.12 (m, 2H), 7.76-7.72 (m, 1H), 7.60-7.64 (m, 1H), 7.53 (s, 1H), 5.70 (sb, 1H), 4.50-4.52 (m, 1H), 4.08 (s, 3H), 3.80-3.90 (m, 2H), 2.71-2.68 (m, 1H), 2.46-2.40 (m, 1H), 1.48 (s, 9H); MS: MS m/z 389.8 (M++1).

Workup

  1. customThe reaction mass was quenched with aqueous citric acid solution
  2. extractionextracted with ethyl acetate (50 mL×3)
  3. washThe combined organics were washed with water, brine solution
  4. dry with materialdried over anhydrous Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customto get crude compound
  8. customThe crude compound was purified by silica gel chromatography (55% ethyl acetate in pet-ether)

Sources & evidence

ORD record
ord-a0f50dcaf87c4c71858ce9e67b76f64b
Source dataset
uspto-grants-2015_02
Patent number
US08957203B2

Reaction notes

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