Acetic Acid → ethyl N-(3-amino4-chloro-6-fluoro-2-methoxyphenyl)carbamate

Beteiligte Stoffe

Reaktionsschritte

Under a nitrogen atmosphere, a stirred solution of 21.3 grams (0.072 mole) of ethyl N-(4-chloro-6-fluoro-2-methoxy-3-nitrophenyl)carbamate, 18.3 grams (0.328 mole) of iron powder, 50 mL of acetic acid, and 250 mL of ethanol was heated to 65° C. where it stirred for two hours. At the conclusion of this time, 3 mL (0.036 mole) of 12 M hydrochloric acid was added. Upon completion of addition, the reaction mixture was stirred for an additional two hours. After this time, the reaction mixture was concentrated under reduced pressure to yield a brown oil. The oil was then taken up in methylene chloride. The mixture was filtered through diatomaceous earth, and the filter cake was washed with water and an aqueous saturated sodium bicarbonate solution. The filtrate was stored over sodium sulfate for about 18 hours and then filtered. The solvent was removed under reduced pressure to yield a black oil. This oil was filtered through a silica gel pad, yielding 15.0 grams of ethyl N-(3-amino-4-chloro-6-fluoro-2-methoxyphenyl)carbamate. The NMR spectrum was consistent with the proposed structure.

Herkunft & Nachweise