1: ethyl acetoacetate With sodium hydride in tetrahydrofuran T=20°C; 0.666667 h; 2: 1-benzotriazol-1-yl-hexan-1-one in tetrahydrofuran T=20°C; 14 h; 3: With ammonium hydroxide; ammonium chloride in tetrahydrofuran; water 1 h; Heating;