Boron tribromide → HCID 21079763, compound

Temperature

-78 °C

step 3—A solution of 16 (3.38 g; 14.30 mmol) and CH2Cl2 (150 mL) were cooled to −78° C. and a solution of BBr3 (5.41 mL; 57.22 mmol) in 130 mL of CH2Cl2 were added dropwise over a 30 m period. The reaction mixture was stirred at −78° C. for 1 h, allowed to warm to rt for 4 h and re-cooled to −78° C. and carefully quenched with sat'd. NaHCO3 (80 mL). The aqueous layer was extracted with CH2Cl2 (1×100 mL), EtOAc (50 mL) and the combined aqueous layers washed with water and brine, dried (Na2SO4) and evaporated to yield a light brown oil. The phenol was purified by silica gel chromatography and eluted with CH2Cl2:hexane (3:1) to CH2Cl2 to CH2Cl2:EtOAc (100:4) to yield ethyl 4-iso-propyl-3hydroxyphenylacetate (18a; 3.0 g; 94%)

1. temperatureto warm to rt for 4 h
2. temperaturere-cooled to −78° C.
3. customcarefully quenched with sat'd
4. extractionThe aqueous layer was extracted with CH2Cl2 (1×100 mL), EtOAc (50 mL)
5. washthe combined aqueous layers washed with water and brine
6. dry with materialdried (Na2SO4)
7. customevaporated
8. customto yield a light brown oil
9. customThe phenol was purified by silica gel chromatography
10. washeluted with CH2Cl2:hexane (3:1) to CH2Cl2 to CH2Cl2:EtOAc (100:4)

ORD record

ord-abb1c581467d4fffae58d62ec70f49a7

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07625949B2