Method for the synthesis of 3-R-1,4,2-dioxazol-5-ones
Provided are methods of preparing 3-R-1,4,2-dioxazol-5-one compounds using convenient and efficient methods. Also provided are 3-R-1,4,2-dioxazol-5-one compounds produced using the methods described.
1 . A method of preparing a 3-R-1,4,2-dioxazol-5-one compound, comprising:
combining a first reaction mixture, a second reaction mixture and a third reaction mixture to form a fourth reaction mixture, the first reaction mixture comprising hydroxylamine hydrochloride, triethylamine, and a first organic solvent, the second reaction mixture comprising an R-substituted acyl chloride, the third reaction mixture comprising triethylamine;
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.
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 selected from the group consisting of N,N-dimethylformamide (DMF), ethyl acetate, and combinations thereof.
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, tetrahydrofuran, and combinations thereof.
6 . The method of claim 1 , further comprising adding an additional amine compound to the second reaction mixture.
7 . The method of claim 6 , further comprising dissolving the additional amine compound in a third organic solvent prior to adding the additional amine compound to the second reaction mixture.
8 . The method of claim 7 , wherein the third organic solvent is selected from the group consisting of ethyl acetate, tetrahydrofuran, and combinations thereof.
9 . The method of claim 1 , further comprising adding an acid to the third reaction mixture prior to obtaining the 3-R-1,4,2-dioxazol-5-one compound.
10 . The method of claim 1 , wherein obtaining the 3-R-1,4,2-dioxazol-5-one compound comprises filtration.
11 . 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. %.
12 . The method of claim 1 , further comprising purifying the 3-R-1,4,2-dioxazol-5-one compound to a purity of at least 90 wt. %.
13 . The method of claim 1 , wherein the method is performed at an ambient temperature and pressure.
14 . The method of claim 1 , wherein the first reaction mixture is cooled to 0° C.
15 . 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.
16 . The method of claim 1 , wherein the 3-R-1,4,2-dioxazol-5-one compound is 3-methyl-1,4,2-dioxazol-5-one or 3-phenyl-1,4,2-dixoazol-5-one.
17 . A one-pot method of preparing a 3-R-1,4,2-dioxazol-5-one compound, comprising:
combining hydroxylamine hydrochloride, triethylamine, a first organic solvent and a second organic solvent to form a first reaction mixture;
adding an R-substituted acyl chloride and additional triethylamine to the first reaction mixture to form a second reaction mixture;
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.
18 . The one-pot method of claim 17 , wherein the first organic solvent is selected from the group consisting of N,N-dimethylformamide (DMF), ethyl acetate, and combinations thereof.
19 . The one-pot method of claim 17 , wherein the second organic solvent is selected from the group consisting of ethyl acetate, tetrahydrofuran, and combinations thereof.