Hydrochloric Acid → ethyl 2-(5-bromo-2,4-dimethoxybenzoyl)-3-((S)-1-hydroxymethyl-2-methylpropylamino)acrylate

Participants

Reaction Steps

Under a nitrogen atmosphere, to a solution of ethyl 2-(5-bromo-2,4-dimethoxybenzoyl)-3-dimethylaminoacrylate obtained in Step 4 of Example 1 in toluene was added L-valinol (20.6 g). After stirring at room temperature for 1 hr, the completion of the reaction was confirmed by HPLC. 1 mol/L Hydrochloric acid (200 mL) was added to the reaction mixture, and after stirring, the toluene layer was separated. The toluene layer was further washed successively with 1 mol/L hydrochloric acid (200 mL), water (200 mL), 5% aqueous sodium hydrogencarbonate solution (200 mL) and water (200 mL). After washing, toluene was evaporated under reduced pressure, toluene (200 mL) was added to the concentrated residue, and the mixture was concentrated again under reduced pressure. THF (200 mL) was further added to the concentrated residue, and the mixture was concentrated again under reduced pressure. THF (160 mL) was added to the obtained concentrated residue to give ethyl 2-(5-bromo-2,4-dimethoxybenzoyl)-3-((S)-1-hydroxymethyl-2-methylpropylamino)acrylate as a tetrahydrofuran solution. The solution was directly used in the next step.

Provenance & Evidence