2-Chloro-N,N-dimethylethylamine → N-carbobenzyloxi-gamma-tert.butyl-L-glutamic acid-dimethylaminoethyl ester

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Reaction Conditions

Reaction Steps

To 1.88 g N-carbobenzyloxy-γ-tert.butyl-L-glutamic acid-dicyclohexyl ammonium salt, 24 ml ethyl acetate and 3.3 ml solution of dimethylaminoethylchloride in the amount of 0.78 g, stoichiometrically corresponds to two times the molar volume, in benzene were added to be subjected to reflux in oil bath at 90° C. for 16 hrs. After cooling down to a room temperature, precipitated dicyclohexyl ammonium chloride was filtered off and ethyl acetate phase in the filtrate was washed with diluted hydrochloride to remove excessive dimethylaminoethylchloride contained therein. The filtrate was further washed with 10% aqueous solution of hydrogen sodium bicarbonate so as to remove unreacted starting meterial, N-carbobenzyloxy-γ-tert.butyl-L-glutamic acid-dicyclohexyl-ammonium salt and then with saturated brine to be neutral, which was then treated with sulfuric sodium anhydride for dehydration and subjected to reduced pressure distillation so as to distill off ethyl acetate and obtain Intermediate I, N-carbobenzyloxy-γ-tert.butyl-L-glutamic acid-dimethylamino-ethyl ester in the amount of 1.43 g (yield; 96.6% by weight).

Provenance & Evidence