Multi-step reaction with 6 steps
1: 88 percent / N-bromosuccinimide, triphenylphosphine / tetrahydrofuran / 2 h / Ambient temperature
2: 75 percent / 2 h / 140 °C
3: 1.) potassium tert-butoxide / 1.) THF-DMSO, 2.) r.t., occasional sonication, 50 min
4: 92 percent / hydrogen / 10 percent Pd-C / ethanol / 24 h / 2942.03 Torr / Ambient temperature
5: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 15 min, 2.) -78 deg C, 5 min, then r.t., 20 min
6: 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
With
N,N,N,N,N,N-hexamethylphosphoric triamide; N-Bromosuccinimide; oxalyl dichloride; potassium tert-butylate; hydrogen; dimethyl sulfoxide; triethylamine; triphenylphosphine; lithium diisopropyl amide;
palladium on activated charcoal;
In
tetrahydrofuran; ethanol;
DOI:10.1248/cpb.39.18