Potassium Phosphate, Tribasic → Methyl 2-amino-5-({1-[3-(2-tert-butoxy-2-oxoethoxy)phenyl]-2-methylindolizin-3-yl}carbonyl)benzoate

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Reaction Conditions

Reaction Steps

The mixture of 2.78 g (7.18 mmol) of methyl 2-amino-5-[(1-bromo-2-methylindolizin-3-yl)carbonyl]benzoate (described in Patent Application WO2005028476), 3.6 g (10.8 mmol) of tert-butyl[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy]acetate (CAS 769968-18-5; described in Patent Application WO2004084813), 0.73 g (1.0 mmol) of PdCl2(dppf) in 22 ml of a molar solution of potassium phosphate and 100 ml of 1,2-dimethoxyethane is heated at 100° C. under argon. After 2 hours and 4 hours, a further 100 mg of PdCl2(dppf) are added. After 6 hours at 100° C. under argon, the reaction medium is allowed to return to ambient temperature and is then filtered. The organic solution is washed with water and with a saturated solution of sodium chloride, dried over sodium sulphate and concentrated to dryness. The residue obtained is purified by flash chromatography on silica gel (dichloromethane/diisopropyl ether gradient=100/0 to 0/100), to give 2.84 g (77%) of a yellow powder.

Provenance & Evidence