Multi-step reaction with 8 steps
1: 46 percent / PPTS / dimethylformamide / 24 h
2: 1.) Bu2SnO / 1.) MeOH, reflux, 3 h, 2.) DMF, 100 deg C, 20 min
3: 81 percent / pyridine / Ambient temperature
4: 85 percent / NaBH3CN, mol. sieves 3A, TFA / dimethylformamide / 48 h / 0 - 20 °C
5: 90 percent / NaH / dimethylformamide / 3 h / -15 °C
6: 87 percent / DDQ / CH2Cl2; H2O / 5 h / Ambient temperature
7: 100 percent / pyridine / 7 h / Ambient temperature
8: 90 percent / NaN3 / dimethylformamide / 32 h / 20 - 40 °C
With
pyridine; sodium azide; 3 A molecular sieve; pyridinium p-toluenesulfonate; sodium hydride; di(n-butyl)tin oxide; sodium cyanoborohydride; trifluoroacetic acid; 2,3-dicyano-5,6-dichloro-p-benzoquinone;
In
dichloromethane; water; N,N-dimethyl-formamide;
DOI:10.1016/S0968-0896(96)00180-0