Multi-step reaction with 9 steps
1: 67 percent / tetrahydrofuran / 5 h / 25 °C
2: (COCl)2 / CH2Cl2 / 1.) 0 deg C, 10 min, 2.) 25 deg C, 1.5 h, 3.) reflux, 30 min
3: 2.) HBr / 1.) Et2O, 0 deg C, 45 min, 2.) AcOH, 0 deg C, 1 h
4: 55 percent / tetrahydrofuran / 25 °C
5: 4.23 g / thiourea / propan-2-ol / 0.5 h / Heating
6: 61 percent / i-Pr2NEt, DMAP / CH2Cl2 / 1.) 0 deg C, 45 min, 2.) 25 deg C, 16 h
7: 59 percent / NaHMDS / tetrahydrofuran / -78 °C / 1.) 45 min, 2.) 2 h
8: TFA / CH2Cl2 / 1.) 0 deg C, 30 min, 2.) 25 deg C, 3 h
9: i-Pr2NEt, BOP*PF6 / dimethylformamide / 25 h / 25 °C
With
dmap; oxalyl dichloride; hydrogen bromide; sodium hexamethyldisilazane; (benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate; N-ethyl-N,N-diisopropylamine; thiourea; trifluoroacetic acid;
In
tetrahydrofuran; dichloromethane; N,N-dimethyl-formamide; isopropyl alcohol;
DOI:10.1016/S0968-0896(98)00265-X