tert-Butyl bromoacetate → HCID 57500346, compound

Participants

Reaction Steps

5.4 ml (9.31 mmol) of potassium hexamethyldisilylamide (0.5 M solution in toluene) and then 0.69 ml (4.66 mmol) of tert-butyl 2-bromoacetate are added, dropwise, to the solution of 1.50 g (4.23 mmol) of methyl 2-amino-5-[(8-hydroxy-1-methoxy-2-methylindolizin-3-yl)carbonyl]benzoate (Stage F of Example 1) in 15 ml of tetrahydrofuran at −20° C. under argon. The mixture is stirred for 2 hours, allowing it to return to ambient temperature. The reaction medium is poured into a saturated aqueous solution of potassium hydrogen sulphate and the mixture is extracted with ethyl acetate. The organic phase is washed with a saturated aqueous solution of sodium chloride, dried over sodium sulphate, and concentrated under reduced pressure. The oil obtained is purified by flash chromatography on silica gel (dichloromethane/methanol gradient=100/0 to 90/10). 1.26 g (64%) of a yellow powder are obtained.

Provenance & Evidence