Method for preparing 5-methylthienyl-2-thiol from levulinic acid

[0031] Add 0.23g of levulinic acid to 15mL of toluene, and add Lawson's reagent twice the amount of the raw material, and react at 100°C for 5h under 1bar nitrogen atmosphere to obtain a light yellow transparent liquid. The solution was washed with 2 times the volume of sodium carbonate solution with a mass concentration of 10%, and then separated by vacuum distillation to obtain 5-methylthiophene-2-thiol with a yield of 62%.

[0033] Add 0.06 g of levulinic acid to 10 mL of xylene, and add Lawson's reagent in an amount 1 times that of the raw material, and react for 1 h at 110° C. under a nitrogen atmosphere of 1 bar to obtain a light yellow transparent liquid. The solution was washed with 1 volume of sodium hydrogen carbonate solution with a mass concentration of 5%, and then separated by vacuum distillation to obtain 5-methylthiophene-2-thiol with a yield of 46%.

[0035] Add 0.6 g of levulinic acid to 20 mL of toluene, and add 1.5 times the amount of Lawson's reagent as the raw material, and react at 110 ° C for 4 h in an air atmosphere of 1 bar to obtain a light yellow transparent liquid. The liquid was washed with 3 times volume of sodium carbonate solution with a mass concentration of 7.5%, and then separated by vacuum distillation to obtain 5-methylthiophene-2-thiol with a yield of 64%.