10 palladium on carbon; hydrogen in methanol 7 h;

1: 1.) triethylamine, isobutyl chloroformate, 2.) ammonia / 1.) chloroform, 0 deg C, 2 h, 2.) chloroform, RT, overnight 2: 87.3 percent / hydrogen / 10percent palladium on carbon / methanol / 9 h / Ambient temperature View Scheme

1: sodium hydroxide / H2O / Ambient temperature 2: 1.) triethylamine, isobutyl chloroformate, 2.) ammonia / 1.) chloroform, 0 deg C, 2 h, 2.) chloroform, RT, overnight 3: 87.3 percent / hydrogen / 10percent palladium on carbon / methanol / 9 h / Ambient temperature View Scheme

1: With trifluoroacetic acid T=25°C; 2: With N-ethyl-N,N-diisopropylamine in dichloromethane T=25°C;

formic acid; triethylamine in dichloromethane

sodium hydroxide in tetrahydrofuran

lithium aluminium tetrahydride in tetrahydrofuran 33 h; Heating;

lithium aluminium tetrahydride in tetrahydrofuran 33 h; Heating;