Uses
tert-Butyl phenyl carbonate is used in determination of octanol-water partition coefficients by microemulsion electrokinetic chromatography. It is also used in the synthesis of 2-nitroindoles and as a reagent for mono-Boc protection of α,ω-diamines.
Synthesis
GENERAL METHOD: Di-tert-butyl dicarbonate (Boc2O, 1.0 mmol) was added to a round-bottomed flask containing phenol (1.0 mmol) and magnesium bromide ethyl ether compound (MgBr2-OEt2, 0.1 mmol). After gas escape was observed, the reaction mixture was magnetically stirred at room temperature (heated to about 60 °C if necessary). The progress of the reaction was monitored by thin-layer chromatography (TLC) and left until the phenol was completely consumed (reaction time was usually 3-16 h). Upon completion of the reaction, the mixture was diluted with water and extracted with ethyl acetate (EtOAc, 3 x 20 mL). The organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using a gradient elution of 5-30% ethyl acetate/hexane to afford the target product tert-butyl phenyl carbonate.
Purification Methods
If IR is free from OH, then purify it by redistillation; otherwise dissolve it in Et2O, wash it with 5% HCl, then H2O, dry it (MgSO4), evaporate and distil it through a Claisen head under vacuum. Care should be taken as distillation of large quantities can lead to decomposition with liberation of CO2 and isobutylene; use the necessary precautions. [Carpino J Am Chem Soc 79 98 1957, Beilstein 6 IV 629.]
References
[1] Green Chemistry, 2011, vol. 13, # 2, p. 436 - 443
[2] Canadian Journal of Chemistry, 1985, vol. 63, p. 153 - 162
[3] Canadian Journal of Chemistry, 1985, vol. 63, p. 153 - 162
[4] Organic Letters, 2005, vol. 7, # 3, p. 427 - 430
[5] Synlett, 2006, # 13, p. 2104 - 2108
