Multi-step reaction with 9 steps
1: 1.) NMM, isobutyl chloroformate / 1.) THF, from -40 deg C to -20 deg C, 1.5 h, 2.) THF, RT, 1.5 h
2: 2,6-lutidine / tetrahydrofuran / 16 h / Ambient temperature
3: 81 percent / N2H4*H2O / 3 h / Heating
4: 48 percent / 24 h / 120 °C / 1 Torr
5: 96 percent / LiI / pyridine / 14 h / Heating
6: 84 percent / diphenyl phosphoroazidate, TEA / dioxane / 4 h / Heating
7: 53 percent / aq. LiOH*H2O / ethanol / 7 h / 0 °C
8: 1.) isobutyl chloroformate, NMM / 1.) THF, from -40 deg C to -30 deg C, 1 h, 2.) THF, RT, 16 h
9: dimethylformamide / 16 h / 120 °C
With
4-methyl-morpholine; 2,6-dimethylpyridine; lithium hydroxide; TEA; diphenyl phosphoryl azide; hydrazine hydrate; lithium iodide; isobutyl chloroformate;
In
tetrahydrofuran; 1,4-dioxane; pyridine; ethanol; N,N-dimethyl-formamide;
DOI:10.1021/jm950684z