1: With triethyl phosphite T=130°C; 4 h; 2: With sodium methylate in tetrahydrofuran; methanol 0.333333 h; Heating;

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

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