Ethyl bromoacetate → Acetic acid, 2-(2-chloro-4-nitrophenoxy)-, ethyl ester

Beteiligte Stoffe

Reaktionsschritte

The product was prepared by the alkylation of 2-chloro-4-nitrophenol (17.35 g) in DMF (150 mL) with ethyl bromoacetate (16.7 g) in the presence of potassium carbonate (13.8 g) to afford 19.6 g (75.6%) of ethyl 4-nitro-2-chlorophenoxyacetate as a white solid, m.p. 73°-74° C.; hydrogenation of the latter (10.0 g, 38.5 mmol) in ethanol (200 mL) on a Parr hydrogenator in the presence of 5% platinum on carbon (sulfided) (200 mg) afforded 8.1 g (92%) of ethyl 4-amino-2-chlorophenoxyacetate, m.p. 59°-62° C., after recrystallization from tert-butylmethylether, and finally, treatment of the latter (7.3 g, 31.8 mmol) in CH2Cl2 (75 mL) at 5° C. with pyridine (3.0 mL, 38.7 mmol) and methanesulfonyl chloride (2.29 mL) to afford N-[4-(ethoxycarbonylmethoxy)-3-chlorophenyl]methanesulfonamide, m.p. 87°-88° C. after recrystallization from tert-butylmethylether.

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