1: diisopropylethylamine / acetonitrile / 0.67 h / -5 °C 2: H2 / 10percent Pd / C / tetrahydrofuran; H2O / 1.67 h / 3040 Torr / Ambient temperature 3: ethyl formimidate hydrochloride, 1N NaOH / tetrahydrofuran; H2O / 0.08 h / 0 °C View Scheme

1: diisopropylethylamine / acetonitrile / 0.5 h / -10 °C 2: diisopropylethylamine / acetonitrile / 0.67 h / -5 °C 3: H2 / 10percent Pd / C / tetrahydrofuran; H2O / 1.67 h / 3040 Torr / Ambient temperature 4: ethyl formimidate hydrochloride, 1N NaOH / tetrahydrofuran; H2O / 0.08 h / 0 °C View Scheme

1: H2 / 10percent Pd / C / tetrahydrofuran; H2O / 1.67 h / 3040 Torr / Ambient temperature 2: ethyl formimidate hydrochloride, 1N NaOH / tetrahydrofuran; H2O / 0.08 h / 0 °C View Scheme

potassium phosphate buffer; hydrogen; N-ethyl-N,N-diisopropylamine; palladium on activated charcoal 1.) DMF, MeOH, 0 deg C to 5 deg C, 25 min, 2.) n-butanol, EtOAc, water, 3.2 kg/cm2, 2 h; Yield given. Multistep reaction;