Hydrochloric Acid → HCID 57500409, compound

Participants

Reaction Steps

12 ml (6.0 mmol) of potassium hexamethyldisilylamide (0.5 M solution in toluene) at −20° C. under nitrogen is added, dropwise, to the solution of 2.0 g (5.64 mmol) of methyl 2-amino-5-[(8-hydroxy-1-methoxy-2-methyl-indolizin-3-yl)carbonyl]benzoate (described in stage F of Example 1) in 56 ml of tetrahydrofuran. The formation of a red precipitate is observed. The mixture is allowed to return to ambient temperature and 18.5 g (33.9 mmol) of 1,20-diiodo-3,6,9,12,15,18-hexaoxaicosane are added (Example R1). The solution is stirred at ambient temperature for 18 hours. The reaction medium is poured into a solution of hydrochloric acid (1 M) and the mixture is extracted with an ethyl acetate/tetrahydrofuran mixture. The organic phase is washed with a saturated aqueous solution of sodium chloride, dried over sodium sulphate and concentrated under reduced pressure. The residue obtained is purified by flash chromatography on silica gel (gradient of dichloromethane/methanol: 100/0 to 90/10). 2.3 g (53%) of a yellow oil are obtained.

Provenance & Evidence