Method for the synthesis of 3-R-1,4,2-dioxazol-5-ones

1. A method of preparing a 3-R-1,4,2-dioxazol-5-one compound, comprising:

providing a first reaction mixture comprising hydroxylamine hydrochloride, triethylamine, and a first organic solvent;

providing a second reaction mixture comprising an R-substituted acyl chloride;

providing a third reaction mixture comprising triethylamine;

combining the first, second and third reaction mixtures to form a fourth reaction mixture;

adding N,N′-carbonyldiimidazole to the fourth reaction mixture to form a fifth reaction mixture; and

obtaining a 3-R-1,4,2-dioxazol-5-one compound from the fifth reaction mixture, wherein the method is performed by a one-pot method.

2. The method of claim 1 , wherein the R-substituted acyl chloride is selected from the group consisting of benzoyl chloride, 2-thiophenecarbonyl chloride, p-toluoyl chloride, 2-naphthoyl chloride, p fluorobenzoyl chloride, m-fluorobenzoyl chloride, o-fluorobenzoyl chloride, p methoxybenzoyl chloride, p-nitrobenzoyl chloride, m-nitrobenzoyl chloride, o-nitrobenzoyl chloride, p-teraphthaloyl chloride, p-chlorobenzoyl chloride, m-chlorobenzoyl chloride, o chlorobenzoyl chloride, and combinations thereof.

3. The method of claim 1 , wherein the first organic solvent is N,N-dimethylformamide (DMF).

4. The method of claim 1 , further comprising dissolving the R-substituted acyl chloride in a second organic solvent to form the second reaction mixture.

5. The method of claim 4 , wherein the second organic solvent is selected from the group consisting of ethyl acetate and tetrahydrofuran.

6. The method of claim 1 , wherein the 3-R-1,4,2-dioxazol-5-one compound is obtained at a purity of at least 50 wt. %.

7. The method of claim 1 , further comprising purifying the 3-R-1,4,2-dioxazol-5-one compound to a purity of at least 75 wt. %.

8. The method of claim 7 , further comprising purifying the 3-R-1,4,2-dioxazol-5-one compound to a purity of at least 90 wt. %.

9. The method of claim 1 , wherein the method is performed at ambient temperature and pressure.

10. The method of claim 1 , wherein the first reaction mixture is cooled to 0° C.

11. The method of claim 1 , wherein the 3-R-1,4,2-dioxazol-5-one compound is selected from the group consisting of 3-phenyl-1,4,2-dioxazol-5-one, 3-thiophene-1,4,2-dioxazol-5-one, 3-tolyl-1,4,2-dioxazol-5-one, 3-(2-naphthyl)-1,4,2-dioxazol-5-one, 3-(p-fluorophenyl)-1,4,2-dioxazol-5-one, 3-(m-fluorophenyl)-1,4,2-dioxazol-5-one, 3-(o-fluorophenyl)-1,4,2-dioxazol-5-one, 3-(p-methoxyphenyl)-1,4,2-dioxazol-5-one, 3-(p-nitrophenyl)-1,4,2-dioxazol-5-one, 3-(m-nitrophenyl)-1,4,2-dioxazol-5-one, 3-(o-nitrophenyl)-1,4,2-dioxazol-5-one, 3,3′-(1,4-phenylene)-bis-1,4,2-dioxazol-5-one, 3-(p-chlorophenyl)-1,4,2-dioxazol-5-one, 3-(m-chlorophenyl)-1,4,2-dioxazol-5-one, 3-(o-chlorophenyl)-1,4,2-dioxazol-5-one, and combinations thereof.

12. The method of claim 1 , further comprising dissolving the triethylamine in a third organic solvent to form the third reaction mixture.

13. The method of claim 7 , wherein the third organic solvent is selected from the group consisting of ethyl acetate, tetrahydrofuran, and combinations thereof.

14. The method of claim 1 , further comprising adding an acid to the fifth reaction mixture prior to obtaining the 3-R-1,4,2-dioxazol-5-one compound.

15. A method of preparing a 3-R-1,4,2-dioxazol-5-one compound, comprising:

combining hydroxylamine hydrochloride, triethylamine, N,N-dimethylformamide (DMF) and ethyl acetate to form a first reaction mixture, wherein the first reaction mixture is cooled to 0° C.;

adding an R-substituted acyl chloride and additional triethylamine to the first reaction mixture to form a second reaction mixture, wherein the second reaction mixture is warmed to room temperature;

adding N,N′-carbonyldiimidazole to the second reaction mixture to form a third reaction mixture;

adding an acid to the third reaction mixture to form a quenched reaction mixture; and

obtaining a 3-R-1,4,2-dioxazol-5-one compound from the quenched reaction mixture, wherein the method is performed by a one-pot method.