Reactions of tetrafluoroethene oligomers. Part 7. Some reactions of 4-diazo-1,1,1,2,2-pentafluoro-3-pentafluoroethyl-3-trifluoromethylbutane

Abstract

The title diazo compound (1) alone or in the presence of Cu²⁺ ions reacted with trifluoroacetic acid to give CF₃(C₂F₅)₂CCH₂O₂CCF₃(2). Careful hydrolysis of (2) with dilute alkali afforded CF₃(C₂F₅)₂CCH₂OH (3) which on oxidation gave the corresponding aldehyde (4). Treatment of (3) with stronger base yielded CF₃(C₂F₅)₂CH (5) and CF₃C₂F₅CCFCF₃(6). Reaction of (1) with acetic acid in the presence of Cu²⁺ ions produced the unexpected compound CF₃C₂F₅CCHOCOCH₃(7) and a trace of CF₃(C₂F₅)₂CCHCFCF₃(13). In a similar reaction chloroacetic acid gave CF₃(C₂F₅)₂CCH₂OCOCH₂Cl (8) and CF₃C₂F₅CCHOCOCH₂Cl (9) in the ratio 4:1. Treatment of (1) with concentrated sulphuric acid gave the dialkyl sulphate [CF₃(C₂F₅)₂CCH₂]₂SO₄(12). Reaction of (1) with methanol/Cu²⁺ or ethanol/Cu²⁺ gave mainly CF₃C₂F₅CCHOMe (10) and CF₃C₂F₅CCHOEt (11) respectively. Reflux of (1) in acetone/Cu²⁺ gave only the olefin (13). No reaction occurred in ether or hexane at their reflux temperatures.