Ethyl chloroformate → HCID 56956917, compound

Participants

Reaction Steps

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).

Provenance & Evidence