N-bromosuccinmide in tetrachloromethane 1 h; HeatingIrradiation;

phosphorus tribromide in tetrahydrofuran; tetrachloromethane

1: N,N-dimethyl-formamide / |Inert atmosphere 2: 2,3-dicyano-5,6-dichloro-p-benzoquinone / toluene / |Inert atmosphere; |Reflux View Scheme

1: N,N-dimethyl-formamide / |Inert atmosphere 2: 2,3-dicyano-5,6-dichloro-p-benzoquinone / toluene / |Inert atmosphere; |Reflux 3: triethyl phosphite / 130 °C / |Inert atmosphere 4: sodium methylate; methanol / tetrahydrofuran / |Inert atmosphere View Scheme