1: in 1-methyl-pyrrolidin-2-one T=100°C; 2: With potassium tert-butylate in tetrahydrofuran; 1-methyl-pyrrolidin-2-one T=100°C; 3.66667 h; 3: With acetic acid in tetrahydrofuran; 1-methyl-pyrrolidin-2-one; water; toluene T=80°C; 0.166667 h;