Preparation of 1,2-diMagnesiummethylbenzene

The  1,2-dimagnesiummethylbenzene showing below is a useful reagent for metal ligand preparation.
This di-grignard reagent  can be made in high yield from corresponding dichloride compound.

1,2-Dibromomethylbenzene can't be used because it can cause problem.

steps:
1. activate Mg using 1,2-dibromoethane.
2. in diluted solution, slowly add dichloride into Mg in THF. control temperature at rt.
3. allow 8 hr stirring at rt.

yield is over 95% in reports.