Multi-step reaction with 7 steps
1: 75 percent / 2 h / 140 °C
2: 1.) potassium tert-butoxide / 1.) THF-DMSO, 2.) r.t., occasional sonication, 50 min
3: 93 percent / hydrogen / 10 percent Pd-C / ethanol / 24 h / 2942.03 Torr / Ambient temperature
4: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 15 min, 2.) -78 deg C, 5 min, then r.t., 20 min
5: 1.) lithium diisopropylamide, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2 h, 2.) -78 deg C, 1 h, then -15 deg C, 30 min
6: 86 percent / p-toluenesulfonic acid / benzene / 1 h / Heating
7: 89 percent / hydrogen / 10 percent Pd-C / acetone / 6 h / 2574.3 Torr / Ambient temperature
With
N,N,N,N,N,N-hexamethylphosphoric triamide; oxalyl dichloride; potassium tert-butylate; hydrogen; toluene-4-sulfonic acid; dimethyl sulfoxide; triethylamine; lithium diisopropyl amide;
palladium on activated charcoal;
In
ethanol; acetone; benzene;
DOI:10.1248/cpb.39.18