Triethylamine → ((2S,3S)-7-Carbamoyl-1,1-diethyl-3-methoxy-1,2,3,4-tetrahydro-naphthalen-2-yl)-carbamic acid (R)-1-phenyl-ethyl ester

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Reaction Steps

A mixture of carbonic acid 4-nitro-phenyl ester (R)-1-phenyl-ethyl ester (102 g, 357 mmol), N,N-dimethylformamide (200 mL) and triethylamine (32.7 mL, 235 mmol) was stirred at room temperature overnight. To the reaction mixture was added trans-7-amino-8,8-diethyl-6-methoxy-5,6,7,8-tetrahydro-naphthalene-2-carboxylic acid amide hydrochloride (100 g, 320 mmol), N,N-dimethylformamide (320 mL) and triethylamine (98.0 mL, 703 mmol). The reaction mixture was heated at 85° C. for 5 h and then stirred at room temperature overnight. Approximately 90% of the DMF was removed by distillation at 70° C. and the resulting thick oil was cooled to room temperature and then partitioned between ethyl acetate (1.5 L) and diluted brine (500 mL). The organic layer was washed with 1M NaOH (3×500 mL) and dried with Na2SO4. Most of the solvent was removed by rotary evaporation, 3 volumes ethyl acetate were added and resulting slurry was stirred at room temperature for 30 min, filtered and dried to give the title compound (48 g, >99% chemical and optical purity).

Provenance & Evidence