Ethyl chloroformate → HCID 56956917, compound

HRID 631906Notes

Reaction equation

HRID 631906 reaction equation
[Li+].CC([N-]C(C)C)C.[Br:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]#[CH:17])=[CH:12][CH:11]=1.Cl[C:19]([O:21][CH2:22][CH3:23])=[O:20]>C1COCC1>[CH2:22]([O:21][C:19](=[O:20])[C:17]#[C:16][C:13]1[CH:14]=[CH:15][C:10]([Br:9])=[CH:11][CH:12]=1)[CH3:23]

Participants

5

Reactant 3

HCID 10928Ethyl chloroformateHCID 136603Benzene, 1-bromo-4-ethynyl-HCID 2724682Lithium diisopropylamide

Product 1

HCID 56956917HCID 56956917, compoundYield 69.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

LDA solution (2M) in THF (20.71 mL, 41.436 mmol) was added to a stirred solution of 1-bromo-4-ethynyl-benzene (3 g, 16.57 mmol) in dry THF (40 mL) at −70° C. and stirred for 30 min. Ethyl chloroformate (11.81 mL, 74.58 mmol) was added and the mixture was allowed to warm to ambient temperature. Stirring was continued for 2 h. The mixture was cooled, and quenched with saturated NH4Cl solution. THF was evaporated under reduced pressure and the aqueous layer was extracted with ethyl acetate. The organic layer was dried over Na2SO4, concentrated and purified over normal silica gel column chromatography using EtOAc-hexane as eluting solvent to get (4-bromo-phenyl)-propynoic acid ethyl ester (2.9 g, 69.13% yield) as a light yellow liquid. GC-MS: 253 (M+H); 1H-NMR (400 MHz, CDCl3) δ ppm 1.32 (t, J=7.0 Hz, 3H). 4.28 (q, J=7.0 Hz, 2H), 7.43 (d, J=8.4 Hz, 2H), 7.51 (d, J=8.4 Hz, 2H).

Workup

  1. stirringStirring
  2. waitwas continued for 2 h
  3. temperatureThe mixture was cooled
  4. customquenched with saturated NH4Cl solution
  5. customTHF was evaporated under reduced pressure
  6. extractionthe aqueous layer was extracted with ethyl acetate
  7. dry with materialThe organic layer was dried over Na2SO4
  8. concentrationconcentrated
  9. custompurified over normal silica gel column chromatography
  10. washas eluting solvent

Sources & evidence

ORD record
ord-9f698105d2ba4214814df1bbd67a4f72
Source dataset
uspto-grants-2016_04
Patent number
US09321738B2

Reaction notes

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