Multi-step reaction with 4 steps 1.1: 4-methyl-morpholine; isobutyl chloroformate / dichloromethane / 0.17 h / -20 °C1.2: 2.08 h / -20 - 20 °C2.1: trifluoroacetic acid / dichloromethane / 2 h / 20 °C2.2: pH 8 - 103.1: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 2 h / 20 °C4.1: hydrogen / palladium 10 on activated carbon / methanol / 2 h