Trifluoroacetic acid → Ethyl 2-(6-aminochroman-2-yl)acetate

Participants

Reaction Conditions

Reaction Steps

Into the ethyl 2-(6-(tert-butyloxycarbonylamino)chroman-2-yl)acetate toluene solution of Example 3 (7 L) was added 1480 g of trifluoroacetic acid. The solution was warmed to 60° C. for 2 h. After distilling-off about 2 L of toluene under reduced pressure (T≦60° C.), the mixture was cooled to room temperature. About 10 L of 10% (w/w) of aqueous sodium bicarbonate was added slowly to the well-stirred mixture until the pH was above 7. The mixture was stirred for 20 min and the aqueous fraction separated. The aqueous fraction was extracted with 3×1 L of toluene. The combined organic fractions were washed with 3 L of brine, dried over 200 g of anhydrous sodium sulfate, and filtered. The volume of solvent was reduced to 6 L by distillation under reduced pressure (T≦60° C.) to provide a toluene solution of ethyl 2-(6-aminochroman-2-yl)acetate.

Provenance & Evidence