Process for preparing benzisothiazolinones

• US 8,884,024 B1
• Filed: 09/25/2013
• Issued: 11/11/2014
• Est. Priority Date: 09/25/2013
• Status: Active Grant

• Current Assignee: Titan Chemicals Limited
• Original Assignee: Titan Chemicals Limited
• Inventors: Marsh, Ian Roger
• Primary Examiner(s): Shterengarts, Samantha
• Assistant Examiner(s): Aguirre, Amanda L
• Application Number:
  US14/036,260
• Time in Patent Office: 412 Days
• Field of Search: 548/209
• US Class Current: 548/209
• CPC Class Codes: C07D 275/04 condensed with carbocyclic rings or ring systems
• CPC Class Codes: C07D 277/64 with only hydrocarbon or substituted hydrocarbon radicals attached in position 2

Abstract

N-alkylated 1,2-benzisothiazolin-3-ones can be prepared in good yield and good selectivity by reaction of the lithium salt of 1,2-benzisothiazolin-3-one with an electrophilic alkylating agent.

Claims

1. A method of making an N-substituted 1,2-benzisothiazolin-3-one comprising reacting the lithium salt of 1,2-benzisothiazolin-3-one with a compound of formula R—

X where R is C₁-C₈ straight chain or branched alkyl or benzyl and X is selected from the group consisting of Cl, Br, I, SO₃Me, triflate, mesyl, tosyl, besyl and sulfonate which may be substituted by one or more F atoms.

2. The method of claim 1 wherein R is Me or n-Bu.

3. The method of claim 1 wherein R is Me or n-Bu.

4. The method of claim 1 wherein R—

X is selected from the group consisting of Mel, Me₂SO₄ and n-BuBr.

5. The method of claim 1 performed in the presence of a solvent selected from the group consisting of dimethylformamide, tetrahydrofuran, butanone, acetonitrile and acetone.

6. The method of claim 1 wherein said lithium salt of 1,2-benzisothiazolin-3-one is prepared by slurrying lithium hydroxide, 1,2-benzisothiazolin-3-one and a polar liquid.

7. The method of claim 5 wherein said lithium salt of 1,2-benzisothiazolin-3-one is prepared by slurrying lithium hydroxide, 1,2-benzisothiazolin-3-one and a polar liquid.

8. The method of claim 6 wherein said polar liquid is selected from the group consisting of ethanol, methanol, acetone, butanone, isopropanol, water and mixtures thereof.

9. The method of claim 8 wherein said polar liquid is industrial methylated spirits.

10. The method of claim 7 wherein said polar liquid is selected from the group consisting of ethanol, methanol, acetone, butanone, isopropanol, water and mixtures thereof.

11. The method of claim 10 wherein said polar liquid is industrial methylated spirits.