1: With trifluoroacetic acid in dichloromethane T=0 - 20°C; 4 h; 2: With sodium hydrogencarbonate in water; ethyl acetate

1: 1-vinyloxycarbonylpiperazine With 2,2'-azo-bisisobutyronitrile; Merrifield SH resin; reduced by dithiothreitol in N,N-dimethyl-formamide T=80°C; Addition; 2: 4-bromobenzoyl bromide With pyridine Solid phase reaction; 3: With 1,8-diazabicyclo[5.4.0]undec-7-ene; 3-chloro-benzenecarboperoxoic acid in dichloromethane Oxidation; Elimination;

acetic acid in tetrahydrofuran T=20°C; Acylation; 1 h;

1: SOCl2 / Heating 2: AcOH / tetrahydrofuran / 1 h / 20 °C View Scheme

in ethanol; dichloromethane T=20°C;