Hydrochloric Acid → Methyl 3-amino-2-(((2'-cyano-[1,1'-biphenyl]-4-yl)methyl)amino)benzoate

Participants

Reaction Conditions

Reaction Steps

Methyl 2-[[(2′-cyanobiphenyl-4-yl)methyl]amino]-3-nitrobenzoate [MBN] (400 kg) obtained in Reference Example 4(3) and tetrahydrofuran [THF] (1080 kg) were mixed, and the MBN solution was stirred. Tin (400 kg) and 35% hydrochloric acid (1322 kg) were mixed, the mixture was stirred at 25 to 30° C. for about 5 hours, warmed to about 80° C. over about 3 hours, and stirred at about 80° C. for about 8 hours. The resulting stannous chloride solution was added dropwise to the MBN solution at 15 to 25° C. over 5 to 8 hours to carry out reduction reaction at 15 to 25° C. for 2 to 5 hours. After completion of the reaction, the pH of solution was adjusted to 12 with 24% sodium hydroxide (about 2000 L) and flaky sodium hydroxide (about 177 kg). The organic layer was separated, and washed twice with an aqueous sodium bicarbonate solution (950 L) and three times with an aqueous saturated sodium chloride solution (840 L). The organic layer was filtered through a 3μ filter, and the solvent was distilled off. The residue was dissolved in ethyl acetate (540 kg), and concentrated again to give concentrate of methyl 3-amino-2-[[(2′-cyanobiphenyl-4-yl)methyl]animo]benzoate [MBA].

Provenance & Evidence