pyridine T=5°C; 7 h; Reflux;

1: 1,4-dioxane / 1 h / |Cooling; |Reflux 2: dimethyl sulfoxide / 2 h / 157 °C View Scheme

sodium hydrogencarbonate; acetic acid; trichlorophosphate in N-methyl-acetamide; chloroform; water; 2,3-dimethyl aniline

in N-methyl-acetamide; water; acetic acid

1.1: 86 percent / phosphorus oxychloride; N,N-dimethyl-p-toluidine / toluene / 2 h / 100 °C 2.1: LHMDS / tetrahydrofuran / 1.5 h / -35 °C 2.2: N,N-dimethyl-p-toluidine / tetrahydrofuran / 3 h / -40 - -35 °C 2.3: 98 percent / acetic acid / tetrahydrofuran / 6 h / pH 5 - 7 / Heating View Scheme

Multistep reaction;