Triisopropyl borate → HCID 57451826, compound

Temperature

-78 °C

(S)-1-azido-2-(2-bromophenyl)propan-2-ol (8.7 g, 34.0 mmol) and triisopropyl borate (9.4 mL, 40.8 mmol) were dissolved in 170 mL of toluene. The reaction mixture was refluxed with a Dean/Stark apparatus to remove the toluene and the residue was dissolved in 150 mL of dry THF. This solution was cooled to −78° C. and BuLi (25M in Hexanes, 15.6 mL, 39.1 mmol) was added dropwise and stirred for 30 min. The reaction mixture was warmed to room temperature and allowed to stir for 3 hrs before being quenched with 50 mL of 6M HCl and concentrated under vacuum. This was extracted 3× with 100 mL of DCM. The combined organic layers were dried over MgSO4 and evaporated under vacuum. Purified by silica gel chromatography (20-30% Et2O/petroleum ether) to give 2.1 g (30%) of (S)-3-(azidomethyl)-3-methylbenzo[c][1,2]oxaborol-1(3H)-ol as a dark yellow oil.

1. temperatureThe reaction mixture was refluxed with a Dean/Stark apparatus
2. customto remove the toluene
3. dissolutionthe residue was dissolved in 150 mL of dry THF
4. temperatureThe reaction mixture was warmed to room temperature
5. stirringto stir for 3 hrs
6. custombefore being quenched with 50 mL of 6M HCl
7. concentrationconcentrated under vacuum
8. extractionThis was extracted 3× with 100 mL of DCM
9. dry with materialThe combined organic layers were dried over MgSO4
10. customevaporated under vacuum
11. customPurified by silica gel chromatography (20-30% Et2O/petroleum ether)

ORD record

ord-a2abc3eaf3ef44cb8c002437f099d464

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08895534B2