Scalable Solvent free sillylation of alcohols

Procedure

1. Charged 100g of staring alcohol (liquid or solid) to a 1L 4 neck RBF under nitogen atmosphere.
2. Added 2.5 Meq. of imidazole at RT.
3. Stirred at RT for 30 minutes if alcohol liquid and if alcohol is solid, heated the mass to melting point of alcohol or imidazole whichever is higher and stirred for 30 minutes.
4. Set the temperature 50-60 degree and added 1.5Meq. of TBDMSCl in lots.
5. Stirred the reaction mass for 5h and checked TLC/ HPLC analysis.
6. If completed, forward to step 9.
7. If incomplete, added 0.2Meq of TBDMSCl and stirred for 1h more at 50-60 degree.
8. Generally reaction completes as per TLC.
9. Cooled the reaction mixture to RT.
10. 1volume = 100mL MeOH is added to the reaction mass and cooled to 0-5 degree.
11. Stirred the mass at 0-5 degree for 1-2h (thick free salt is observed).
12. Filtered the reaction mass under nitrogen atmosphere and washed the solid (filter) with 0.5Volume = 50mL X2 chilled MeOH.
13. Suck dried under nitrogen.
14. Concentrated the reaction mass under vacuum and dissolved it in 15volume = 1.5L EtOAc.
15. Transferred the organic mass to a 3L 4 neck RBF and added 2volume = 200mL water and cooled to 15-20 degree.
16. Adjusted pH of mixture to 5.8-6.3 with 1N HCl.
17. Stirred, settled and separeted layers.
18. Repeated the above pH treatment once more.
19. Now further added 1volume = 100mL water to the organic layer and adjusted it's pH = 8.5-9.0 with saturated sodium bicarbonate solution.
20. Stirred, settled and separeted layers.
21. Repeated the above pH treatment once more.
22. Concentrated the organic mass.
23. The obtained silylated product can be forwarded to the next step as such or can be purified using recrystallization/ coloumn chromatography.