Methyl iodide → (R)-2-(Boc-amino)-4-pentynoic acid methyl ester

HRID 1175710Notes

Reaction equation

HRID 1175710 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([CH2:13][C:14]#[CH:15])[C:10]([OH:12])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:16](=O)([O-])[O-].[Cs+].[Cs+].CI>CN(C=O)C>[CH3:16][O:11][C:10](=[O:12])[C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[CH2:13][C:14]#[CH:15]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 7009126(2R)-2-(((tert-butoxy)carbonyl)amino)pent-4-ynoic acid

Product 1

HCID 12149490(R)-2-(Boc-amino)-4-pentynoic acid methyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

The commercially available compound, 2-(R)-tert-butoxycarbonylaminopent-4-ynoic acid (0.321 g, 1.50 mmol) was dissolved in anhydrous DMF (5 mL). To the solution was added cesium carbonate (0.54 g, 1.65 mmol) in one portion. The mixture was stirred at room temperature for 45 min before methyl iodide (0.20 mL, 3.00 mmol) was added, and further stirred for three hours. The reaction was quenched with water (10 mL). The organics was extracted with dichloromethane (2×30 mL), washed with water (3×50 mL), and dried over anhydrous sodium sulfate. The solvent was completely removed under vacuum. The residue was further dried under high vacuum over night and used in the next reaction without further purification. The product 23 was obtained as a colorless viscous oil (0.326 g, 95% yield). 1H NMR (300 MHz, CDCl3): δ 1.48 (s, 9H), 2.08 (t, J=2.6 Hz, 1H), 2.75 (t, J=6.3 Hz, 2H), 3.78 (s, 3H), 4.46 (m, 1H), 5.32 (br s, 5H).

Workup

  1. additionwas added
  2. customThe reaction was quenched with water (10 mL)
  3. extractionThe organics was extracted with dichloromethane (2×30 mL)
  4. washwashed with water (3×50 mL)
  5. dry with materialdried over anhydrous sodium sulfate
  6. customThe solvent was completely removed under vacuum
  7. customThe residue was further dried under high vacuum over night
  8. customused in the next reaction without further purification

Sources & evidence

ORD record
ord-3d11432bad3e41c9be894db0a359197c
Source dataset
uspto-grants-2010_11
Patent number
US07842697B2

Reaction notes

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