Diisopropylamine → (3,5-Dichloro-phenyl)-propynoic acid ethyl ester

Temperature

0 °C

To a solution of diisopropylamine (0.23 mL) in THF (0.6 mL) at −78° C. was added a solution of n-butyllithium (0.46 mL, 2.0 M in hexane). The mixture was stirred at −78° C. for 20 minutes, 0° C for 15 min., and cooled to −78° C. To this mixture was added a solution of 1,3-dichloro-5-ethynyl-benzene (136 mg, 0.80 mmol) in THF (1.0 mL) over 2 minutes. After stirring at −78° C. for 1 h, a solution of ethyl chloroformate (0.09 mL) in THF (0.2 mL) was added, and stirred for 1 h at −78° C. The reaction was quenched with saturated ammonium chloride, warmed up to ambient temperature, and extracted with ethyl acetate. The extract was dried over Na2SO4, concentrated, and flash chromatographed on silica gel, eluting with hexane to give the title compound (0.16 g, 87% yield) as a yellow oil. 1H NMR (CDCl3) δ 7.47-7.44 (m, 3H), 4.31 (q, 2H, J=7.2 Hz), 1.36 (t, 3H, J=7.2 Hz).

1. temperaturecooled to −78° C
2. stirringAfter stirring at −78° C. for 1 h
3. stirringstirred for 1 h at −78° C
4. customThe reaction was quenched with saturated ammonium chloride
5. temperaturewarmed up to ambient temperature
6. extractionextracted with ethyl acetate
7. dry with materialThe extract was dried over Na2SO4
8. concentrationconcentrated
9. customflash chromatographed on silica gel
10. washeluting with hexane

ORD record

ord-1d1ae2d078c44ef2b87ee9d27b0c0170

Source dataset

uspto-grants-2005_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06855722B2