Ethyl chloroformate → Ethyl 4-methylpent-2-ynoate

HRID 1689749Notes

Reaction equation

HRID 1689749 reaction equation
[CH3:1][CH:2]([CH3:5])[C:3]#[CH:4].Cl[C:7]([O:9][CH2:10][CH3:11])=[O:8]>O1CCCC1>[CH2:10]([O:9][C:7](=[O:8])[C:4]#[C:3][CH:2]([CH3:5])[CH3:1])[CH3:11]

Participants

4

Reactant 2

HCID 10928Ethyl chloroformateHCID 690193-Methylbut-1-yne

Product 1

HCID 11400823Ethyl 4-methylpent-2-ynoate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3-methylbut-1-yne (6.32 g), cooled in a dry-ice/acetone bath, in tetrahydrofuran (200 mL) is added 1.6 M N-butyl lithium solution (63.8 mL). After 1 h, ethyl chloroformate (9.33 mL) is added and the reaction mixture is stirred for an additional 1.5 h. The reaction mixture is allowed to warm to room temperature and is quenched with saturated ammonium chloride solution. The reaction is extracted two times with ethyl acetate. The organic layers are combined, washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the title compound (11.5 g). 1H NMR (400 MHz, CDCl3) δ 3.75 (s, 3H), 2.8-2.65 (m, 1H), 1.25-1.23 (d, 6H).

Workup

  1. customis quenched with saturated ammonium chloride solution
  2. extractionThe reaction is extracted two times with ethyl acetate
  3. washwashed with brine
  4. dry with materialdried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-7b8277d920c44021924b648a84731919
Source dataset
uspto-grants-2012_04
Patent number
US08153624B2

Reaction notes

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