Multi-step reaction with 6 steps
1: 1.) NaH / 1.) DMF, a) 0 deg C, 10 min, b) 25 deg C, 30 min, 2.) DMF, 75 deg C, 1 h
2: 86 percent / aq. NaOH / methanol; tetrahydrofuran / 16 h / 25 °C
3: 1.) ethyl chloroformate, Et3N / 1.) THF, -15 deg C, 15 min, 2.) THF, a) -10 deg C, 10 min, b) 25 deg C, 30 min
4: 80 percent / p-TsOH*H2O / methanol / 0.5 h / 45 °C
5: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -70 deg C, 30 min, 2.) CH2Cl2, 0 deg C, 5 min
6: 1.) NaH / 1.) THF, a) 0 deg C, 10 min, b) 25 deg C, 30 min, 2.) THF, 25 deg C, 1 h
With
sodium hydroxide; oxalyl dichloride; chloroformic acid ethyl ester; sodium hydride; toluene-4-sulfonic acid; dimethyl sulfoxide; triethylamine;
In
tetrahydrofuran; methanol;
DOI:10.1016/S0968-0896(97)00090-4