Electrochemical production of higher pentafluorosulfonyl acid fluorides

• US 5,286,352 A
• Filed: 07/15/1992
• Issued: 02/15/1994
• Est. Priority Date: 02/28/1990
• Status: Expired due to Fees

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Savu, Patricia M., Hansen, John C.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): IGOE, PATRICK
• Application Number:
  US07/914,427
• Time in Patent Office: 580 Days
• Field of Search: 204/59 F, 204/59 R
• US Class Current: 205/445
• CPC Class Codes: B61F 17/36 with other, e.g. mixed, lubricating agents
• CPC Class Codes: C07C 381/00 Compounds containing carbon and sulfur and having functional groups not covered by groups C07C301/00 - C07C337/00
• CPC Class Codes: C08F 8/18 Introducing halogen atoms or halogen-containing groups
• CPC Class Codes: C25B 3/28 Fluorination
• CPC Class Codes: D06M 11/55 with sulfur trioxide; with sulfuric acid or thiosulfuric acid or their salts
• CPC Class Codes: D06M 13/256 Sulfonated compounds esters thereof, e.g. sultones

Abstract

A continuous process for preparing in a Simons electrochemical cell charged with anhydrous liquid HF and a S- and H-containing organic precursor fluorochemical compounds having the formula F₅ S--R_f --X where X is COF or SO₂ F; R_f is a saturated fluoroaliphatic radical having at least 3 fully-fluorinated C atoms; and the F₅ S group is bonded via a S--C bond to 1 of the 3 fully-fluorinated C atoms of the R_f radical.

Claims

1. A continuous process for preparing fluorochemical compounds, comprising the steps of:

(1) charging a Simons electrochemical cell with anhydrous liquid hydrogen fluoride;

(2) periodically charging the cell with a S- and H-containing organic precursor to form a solution of anhydrous liquid hydrogen fluoride containing the precursor;

(3) electrolyzing the solution to produce a gaseous product mixture containing fluorochemical compounds having the formula F₅ S--R_f --X where X is COF or SO₂ F;

R_f is a saturated fluoroaliphatic radical having at least 3 fully-fluorinated C atoms; and

the F_f S group is bonded via a S--C bond to 1 of the 3 fully-fluorinated C atoms of the R_f radical.

3. The continuous process of claim 1, further comprising:

condensing the gaseous product mixture to obtain a condensate containing the fluorochemical compounds mixed with liquid hydrogen fluoride and phase splitting the condensate to separate the fluorochemical compounds from the liquid hydrogen fluoride.

2. The continuous process of claim 7, wherein:

the precursor is selected from the group consisting of thiophenecarbonyl chloride, thiobutyrolactone, mercaptobenzoic acid, di-thiohexanoyl chloride, 3-methyl-2-thiophene carboxylic acid, 3-methyl-2-thiophene carboxylic acid, and 2-thiophenesulfonylfluoride.