Ethyl chloroformate → (6-Methyl-pyridin-2-yl)-propynoic acid ethyl ester

HRID 902003Notes

Reaction equation

HRID 902003 reaction equation
[C:1]([C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([CH3:9])[N:4]=1)#[CH:2].C([Li])CCC.Cl[C:16]([O:18][CH2:19][CH3:20])=[O:17]>C1COCC1.[Cl-].[NH4+]>[CH2:19]([O:18][C:16](=[O:17])[C:2]#[C:1][C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([CH3:9])[N:4]=1)[CH3:20]

Participants

6

Reactant 3

HCID 10928Ethyl chloroformateHCID 134006352-Ethynyl-6-methylpyridineHCID 178418339Butyllithium

Product 1

HCID 59700610(6-Methyl-pyridin-2-yl)-propynoic acid ethyl esterYield 83%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 25517Ammonium ChlorideSolvent

Procedure

A solution of 2-Ethynyl-6-methyl-pyridine (0.5 g, 4.3 mmol) in THF (20 mL) is cooled to −78° C. and treated with 1.6 M n-butyllithium in hexanes (2.9 mL, 4.7 mmol) and stirred for 0.5 hours. This solution is then treated with ethyl chloroformate (2.85 mL, 30 mmol) and stirred for 3 hours while the solution warms to room temperature The reaction is diluted with saturated aqueous ammonium chloride and extracted with EtOAc. The solvent is concentrated to afford 0.67 g (83%) of desired product as a light yellow oil. UV (95% EtOH) λmax 286 nm (ε 10977), 238 nm (ε 9757). TOF MS ES+ exact mass calculated for C11H11NO2 (p+1): M/z=190.0868. Found: 190.0864.

Workup

  1. stirringstirred for 3 hours while the solution
  2. customwarms to room temperature
  3. extractionextracted with EtOAc
  4. concentrationThe solvent is concentrated

Sources & evidence

ORD record
ord-a5e48b9b0e774f5e9788f005229bc22a
Source dataset
uspto-grants-2008_04
Patent number
US07365066B2

Reaction notes

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