1: 5-ethynyl-4-methyl-2-methylthiopyrimidine With hydroxylamine hydrochloride; N-butylamine; copper(l) chloride in tetrahydrofuran; methanol T=0°C; Metallation; 2: 3-bromopropargyl alcohol in tetrahydrofuran; methanol T=10 - 20°C; Substitution; 5 h; Further stages.;

1.1: 70 percent / EtONa; EtOH / 2 h 2.1: 71 percent / PCl5 / benzene / 3 h / Heating 3.1: 72 percent / t-BuOK / 2-methyl-propan-2-ol; diethyl ether / 4 h / 20 °C 4.1: cuprous chloride; nC4H9NH2; hydroxylamine hydrochloride / tetrahydrofuran; methanol / 0 °C 4.2: 81 percent / tetrahydrofuran; methanol / 5 h / 10 - 20 °C View Scheme

1.1: 72 percent / t-BuOK / 2-methyl-propan-2-ol; diethyl ether / 4 h / 20 °C 2.1: cuprous chloride; nC4H9NH2; hydroxylamine hydrochloride / tetrahydrofuran; methanol / 0 °C 2.2: 81 percent / tetrahydrofuran; methanol / 5 h / 10 - 20 °C View Scheme

1.1: 71 percent / PCl5 / benzene / 3 h / Heating 2.1: 72 percent / t-BuOK / 2-methyl-propan-2-ol; diethyl ether / 4 h / 20 °C 3.1: cuprous chloride; nC4H9NH2; hydroxylamine hydrochloride / tetrahydrofuran; methanol / 0 °C 3.2: 81 percent / tetrahydrofuran; methanol / 5 h / 10 - 20 °C View Scheme

1.1: 87.5 percent / acetic anhydride / 3 h / 130 °C 2.1: 70 percent / EtONa; EtOH / 2 h 3.1: 71 percent / PCl5 / benzene / 3 h / Heating 4.1: 72 percent / t-BuOK / 2-methyl-propan-2-ol; diethyl ether / 4 h / 20 °C 5.1: cuprous chloride; nC4H9NH2; hydroxylamine hydrochloride / tetrahydrofuran; methanol / 0 °C 5.2: 81 percent / tetrahydrofuran; methanol / 5 h / 10 - 20 °C View Scheme