Process for the preparation of dichlorofulvene
View Patent ↗The invention relates to a process for the preparation of formula (I) which process comprises pyrolyzing a compound of formula (II) wherein X is chloro or bromo, and to compounds which may be used as intermediates for the manufacture of the compound of formula I and to the preparation of said intermediates.
1. A process for the preparation of the compound of formula I
which process comprises pyrolysing a compound of formula II
wherein X is chloro or bromo at temperatures of at least 200° C.
2. A process according to claim 1 , wherein the compound of formula II is pyrolysed in a reactor at temperatures of 200 to 1000° C.
3. A process according to claim 2 , wherein the compound of formula II is conveyed to the reactor in gaseous form.
4. A process according to claim 3 , wherein the compound of formula II is conveyed to the reactor under continuous carrier gas flow.
5. A process according to claim 4 , wherein the carrier gas is selected from nitrogen, gaseous hydrogen chloride and gaseous xylene.
6. A process according to claim 2 , wherein the product is transferred after the pyrolysis reaction from the outlet of the reactor into a trap containing an inert solvent.
7. A process according to claim 2 , wherein the reactor and the vessel containing the compound of formula II is kept under reduced pressure.
8. A process according to claim 1 , wherein X is chloro.
9. A compound of formula IIIe
wherein X is chloro or bromo.
10. A compound of formula IIIf
wherein X is chloro or bromo.
11. A process for the preparation of the compound of formula I which process comprises pyrolysing a compound of formula IIIe according to claim 9
12. A process for the preparation of the compound of formula I which process comprises pyrolysing a compound of formula IIIf according to claim 10
13. A process for the preparation of the compound of formula I which process comprises pyrolysing a compound of formula IIIg