Yes, I have just tried this solution:

https://emacs.stackexchange.com/questions/27866/syntax-highlighting-in-org-mode-begin-latex-block/27891

i.e.  

#+BEGIN_LaTeX latex


#+END_LaTeX

and it seems that is the best option for me, but sometimes I meet error with the export into the latex file. But the highlightings works.

Thanks !

Best wishes

2018-05-09 14:05 GMT+02:00 Russell Adams <RLAdams@adamsinfoserv.com>:
On Wed, May 09, 2018 at 01:31:51PM +0200, Joseph Vidal-Rosset wrote:
> But nothing works for highlighting latex.

Have you considered making a latex block, and editing it? It'll have full latex
syntax highlighting while in the block.

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