1.1: N-ethyl-N,N-diisopropylamine / N,N-dimethyl-formamide / 1.5 h / 50 °C 2.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 3 h / 18 - 25 °C 2.2: 0 °C 3.1: N-ethyl-N,N-diisopropylamine; HATU / isobutyramide / 1 h / 18 - 25 °C View Scheme

1.1: N-ethyl-N,N-diisopropylamine / N,N-dimethyl-formamide / 1.5 h / 50 °C 2.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 3 h / 18 - 25 °C 2.2: 0 °C 3.1: N-ethyl-N,N-diisopropylamine; HATU / isobutyramide / 1 h / 18 - 25 °C 4.1: borane-THF / tetrahydrofuran / 18 - 25 °C 4.2: 3 h 4.3: pH ~ 10 View Scheme