pyridine; 2-amino-benzenethiol in dichloromethane 1.5 h; Ambient temperature;

(carboxymethyl)trimethylammonium chloride hydrazide in methanol; ethyl acetate Ambient temperature;

pyridine in dichloromethane Ambient temperature;

1: (i) benzene, (ii) PbO2, 1,2-dichloroethane, (iii) /BRN= 1098229/, benzene 2: Girard T / ethyl acetate; methanol / Ambient temperature View Scheme

1: phosgene-pyridine / CH2Cl2 / Ambient temperature 2: 25 percent / pyridine / CH2Cl2 / Ambient temperature View Scheme

pyridine in dichloromethane 1.5 h; Ambient temperature;

1: phosgene-pyridine / CH2Cl2 / 3 h / Ambient temperature 2: 15 percent / pyridine, o-amino-benzenethiol / CH2Cl2 / 1.5 h / Ambient temperature View Scheme

(i) PhNEt2, 1,2-dichloroethane, (ii) CF3CO2H, anisole; Multistep reaction;

1: With pyridine in dichloromethane T=-30 - -20°C; 1 h; 2: With N-bromosuccinmide in methanol; dichloromethane T=0 - 5°C; 1 h;

1: (6R-cis)-7-amino-3-lt;lt;(1-methyl-1H-tetrazol-5-yl)thiogt;methylgt;-7-(methylthio)-8-oxo-5-thia-1-azabicyclolt;4.2.0gt;oct-2-ene-2-carboxylic acid diphenylmethyl ester; diphenylmethyl (6R,7S)-7-amino-7-methoxy-3-lt;lt;(1-methyl-1H-tetrazol-5-yl)thiogt;methylgt;-Δ3-cephem-4-carboxylate; 2-bromo acetyl bromide With pyridine in dichloromethane T=-30 - -20°C; 1 h; 2: in dichloromethane; water T=0 - 5°C; 3: methanol With N-bromosuccinmide; sodium thiosulfate Purification / work up; more than 3 stages;