The present invention produces an unsaturated compound (Formula 2) useful as a fluororesin starting material and the like by using a compound of the Formula 1 as a starting material.
That is, the present invention provides a method for preparing a compound expressed by CR
b
R
c
═CR
d
R
e
(Formula 2) such as CF
3
CF
2
CF
2
OCF═CF
2
by pyrolyzing a compound having at least one partial structure expressed by —COOCF
2
CR
b
R
c
—CXR
d
R
e
(Formula 1) such as CF
3
CF
2
CF
2
OCF(CF
3
)COOCF
2
CF(CF
3
)OCF
2
CF
2
CF
3
, wherein R
b
to R
e
are a hydrogen atom, a halogen atom or a monovalent organic group unchangeable by pyrolysis reaction.
本发明使用式1化合物作为起始材料,制备一种有用于制备
氟树脂起始材料等的不饱和化合物(式2)。即,本发明提供一种通过热解至少含有一个部分结构为—COO
CF2CRbRc—CXRdRe(式1)的化合物(如
CF3CF2CF2OCF( )COO
CF2CF( )O
CF2CF2 )来制备表达为CRbRc═CRdRe(式2)的化合物(如
CF2CF2OCF═
CF2)的方法。其中,Rb到Re是氢原子,卤素原子或不受热解反应影响的一价有机基团。