| 摘要 |
The process for preparing hexafluoroisobutylene is disclosed which comprises reacting, in the liquid phase, formaldehyde or a formaldehyde-generating compound with hexafluorothioacetone dimer in an aprotic solvent containing at least a catalytic amount of an alkali metal fluoride or a sulfonic acid having general formula RSO3H is disclosed. The preferred aprotic solvents are dimethylformamide, N-methyl pyrrolidone and dimethyl sulfoxide. The preferred alkali metal fluoride is KF; the preferred sulfonic acids are CH3SO3H and p-CH3C6H4SO3H. The production of hexafluoroisobutylene by contacting hexafluoropropene with elemental sulfur and a catalytic amount of an alkali metal fluoride such as KF in an aprotic solvent such as dimethyl sulfoxide or N-methyl pyrrolidone at a temperature of between about 40 DEG and about 70 DEG C. for a time sufficient to produce hexafluorothioacetone dimer combined with contacting said dimer in said aprotic solvent containing said alkali metal fluoride at a temperature between about 100 DEG C. and 150 DEG C. for a time sufficient to produce an effluent stream containing hexafluoroisobutylene which is recovered therefrom is also disclosed. |
