you can check out these links

http://cancerres.aacrjournals.org/content/canres/51/13/3602.full.pdf

https://www.researchgate.net/post/What_are_the_effective_ways_to_synchronize_cells_before_any_cell_based_experiments2

https://www.researchgate.net/post/After_arresting_the_cell_division_of_cancer_cells_in-vitro_what_is_the_maximum_time_period_we_can_keep_them_viable

Article Methods for Synchronizing Cells at Specific Stages of the Cell Cycle

Article Overview of Cell Synchronization

You can use a drug called nocodazole to arrest cells in G2/M phase

Previously we have used RO-3306, to synchronize MEFs.

or look at Article JSAP1 and JLP are required for ARF6 localization to the midb...

You might want to check out Colin Shepherds article in Bitsize

https://bitesizebio.com/33861/perform-cell-synchronization-specific-cell-cycle-phases/

best of luck

martin