Methyl Anthranilate → Methyl 2-(3-oxobutanoylamino)benzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2-amino-benzoic acid methyl ester (1.51 g, 10 mmol) and triethylamine (97.2 mmol/ml, 0.0194 mL, 0.14 mmol, 0.014 eq) in toluene (4 mL) was heated to 60° C. and then a solution of 4-methylene-oxetan-2-one (0.84 g, 10 mmol) in toluene (2 ml) was added to the solution over 15 minutes. The reaction was heated at 80° C. for 6 hours and then at 50° C. for 16 hours. Progress of the reaction was monitored by TLC (silica gel, hexane-ethyl acetate (7:3 v/v)), analytical HPLC and LCMS and upon its completion the mixture was partitioned between ethyl acetate and aqueous hydrochloric acid (1 N). The organic layer was washed with water, saturated sodium bicarbonate, water and then brine, dried over Na2SO4 and concentrated to give an orange solid. The solid was crystalized from methylene chloride/ethyl acetate and hexane to provide 2-(3-oxo-butanoylamino)-benzoic acid methyl ester (1.83 g, 78%) as large colorless prisms, mp 81-83° C. (lit., mp 79-80° C.). LCMS MH+ 235.6.

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