THE SYNTHESIS AND REARRANGEMENT REACTIONS OF 2,3,4,5,6-PENTAFLUOROBENZYL METHYL SULPHOXIDE AND 1,1-BIS(PENTAFLUOROPHENYL)METHYL METHYL SULPHOXIDE

Article abstract of DOI:10.1016/S0022-1139(00)81549-3

2,3,4,5,6-Pentafluorobenzyl methyl sulphoxide (6) and 1,1-bis(pentafluorophenyl)methyl sulphoxide (9) were synthesised from hexafluorobenzene and sodium methylsulphinylmethide.Flash vapour phase thermolysis of (6) at 410 degC gave 2,2',3,3'4,4',5,5'6,6'-decafluorodibenzyl (11) whereas static vapour phase thermolysis at 140-190 deg C gave (11), 2,3,4,5,6-pentafluorobenzyl alcohol (12) and 2,2'3,3'4,4'5,5'6,6'-decafluorodibenzyl disulphide (13).Decaflourobenzophenone (14) and bis(pentafluorophenyl)methanol (15) are thermolysis products of compound (9) at 115-122 deg C, accompanied by 4-methanoyl-nonafluorobenzophenone (16) formed by the thermolysis of (19), the unisolated material derived from (9) by nucleophilic substitution of one para-fluorine by CH3SOCH2^-.Central to the formation of (12), (13), (14), (15) and (16) are sulphenate esters formed by '1,2'-rearrangements, while homolysis of the C-SO(CH3) bond in (6) and dimerisation of the radical gives (11).