Process for preparing 2-alkyl-3aryl-and-heteroaryloxaziridines and novel 2-alkyl-3-aryloxaziridines

• US 20020111339A1
• Filed: 07/05/2001
• Published: 08/15/2002
• Est. Priority Date: 07/07/2000
• Status: Active Grant

• Current Assignee: Lanxess Deutschland GmbH (Lanxess AG)
• Original Assignee: Bayer AG
• Inventors: Klausener, Alexander, Dockner, Michael, Langer, Reinhard, Ratsch, Stephan
• Granted Patent: US 6,740,761 B2
• Time in Patent Office: Days
• US Class Current: 514/183
• CPC Class Codes: C07D 273/00 Heterocyclic compounds containing rings having nitrogen and oxygen atoms as the only ring hetero atoms, not provided for by groups C07D261/00 - C07D271/00

Abstract

2-Alkyl-3-aryl- or -heteroaryloxaziridines are prepared in a particularly advantageous manner by oxidizing corresponding N-alkyl-aryl- or -heteroarylaldimines with an aromatic percarboxylic acid or a salt thereof in the presence of water, a water-soluble base, and a water-miscible solvent, at temperatures below 30° C. Using this method, it is also possible to obtain novel 2-alkyl-3-aryloxaziridines.

Claims

1. A process for preparing a 2-alkyl-aryl- or -heteroaryloxaziridine comprising oxidizing a corresponding N-alkyl-aryl- or -heteroarylaldimine with an aromatic percarboxylic acid or a salt thereof in the presence of water, a water-soluble base, and a water-miscible solvent, at temperatures below 30°

C.

2. A process according to claim 1 wherein an N-alkyl-aryl- or -heteroarylaldimine of the formula (I)

3. A process according to claim 2 wherein one or more alkyl radicals are mono- or polysubstituted by saturated C₃-C₁₂-cycloalkyl, C₆-C₁₀-aryl, C₂-C₈- alkenyl, fluorine, chlorine, bromine, iodine, hydroxyl, C₁-C₆-alkoxy, C₆-C₁₀-aryloxy, carboxyl, C₁-C₆-alkoxycarbonyl, nitro, amido, nitrile, sulfonyl, or phosphate and wherein one or more cycloalkyl, alkenyl, aryl, and heteroaryl radicals are mono- or polysubstituted by C₁-C₆-alkyl, fluorine, chlorine, bromine, hydroxyl, C₁-C₆-alkoxy, carboxyl, C₁-C₆-alkoxycarbonyl, nitro, sulfonyl, or nitrile.

4. A process according to claim 2 wherein in formulas (I) and (II),

R¹, R², and R³ independently of one another each represent hydrogen, straight-chain or branched C₁-C₁₀-alkyl, C₃-C₆-cycloalkyl, straight-chain or branched C₃-C₆-alkenyl, or phenyl or the entire C(R¹)(R²)(R³) group represents C₃-C₆-cycloalkyl, wherein the radicals are not substituted any further, and

X represents phenyl, naphthyl, or furyl, wherein the phenyl and naphthyl radicals may optionally be substituted by one or two identical or different radicals selected from the group consisting of C₁-C₆-alkyl, fluorine, chlorine, bromine, hydroxyl, C₁-C₆-alkoxy-carbonyl, nitro, sulfonyl, and nitrile.

5. A process according to claim 1 wherein the percarboxylic acid or the salt thereof is m-chloroperbenzoic acid or monoperoxyphthalic acid or an alkali metal or magnesium salt thereof.

6. A process according to claim 1 wherein the water-soluble base is an alkali metal or alkaline earth metal oxide, hydroxide, carbonate, bicarbonate, hydrogen phosphate, or dihydrogen phosphate.

7. A process according to claim 1 wherein the water-miscible solvent is a mono- or polyhydric alcohol having up to 6 C atoms.

8. A process according to claim 2 comprising

(1) initially preparing a mixture comprising 5 to 80% by weight of the aldimine of the formula (I) in the water-miscible solvent,

(2) reacting the mixture with the aqueous solution comprising 15 to 30% by weight of a base,

(3) adding a 1 to 20% by weight strength solution of an aromatic percarboxylic acid or a salt thereof to the resulting mixture at such a rate that the reaction temperature does not exceed 30°

C.,

(4) stirring the resulting mixture at from 5 to 30°

C. until the reaction has ended, and

(5) working up the reaction mixture by phase separation or extraction.

9. A process according to claim 2 wherein, based on the aldimine of the formula (I), from 0.09 to 2 equivalents of base and from 0.9 to 1.2 equivalents of active oxygen in the form of an aromatic percarboxylic acid or salt thereof are used.

10. 2-Isopropyl-3-(4-methoxyphenyl)oxaziridine.

11. 2-n-Propyl-3-(4-methoxyphenyl)oxaziridine.