Borane → HCID 14143244, compound

Temperature

4 °C

A flame-dried 2000-mL 3-neck flask fitted with a 250-mL pressure equilibrated dropping funnel, and internal thermometer, and nitrogen inlet is charged with a solution of 4-tert-butyl-6,7 dihydrobenzofuran (24.26 g, 137.8 mmol) in dry tetrahydrofuran (300 mL). The solution is cooled to 4° C. then a solution of borane 1M in tetrahydrofuran, 142 mL) is added dropwise over 20 minutes such that the internal temperature does not exceed 5° C. during the addition. The cooling bath is removed and the reaction mixture is allowed to warm to room temperature and stir for 2.5 hours. The reaction is then quenched by the dropwise addition of water (9.5 mL) followed (after hydrogen evolution was complete) by the addition of 2.5N NaOH (280 mL). Hydrogen peroxide (30% aqueous solution, 16 mL) is carefully added dropwise such that the reaction temperature is about 45° C. upon completion of the addition. An oil bath is added and the reaction mixture maintained at 45°-50° C. for one hour. The reaction mixture is allowed to cool, then diluted with 20% NaCl (500 mL). The layers are separated and the aqueous layer extracted with an additional portion of tetrahydrofuran (300 mL). The combined organic extracts are washed with 20% NaCl (500 mL), dried (MgSO4), and concentrated. Trituration with hexane afforded trans-4-tert butyl-4,5,6,7-tetrahydro-5-benzofuranol.

1. customA flame-dried 2000-mL 3-neck flask fitted with a 250-mL pressure
2. additiondoes not exceed 5° C. during the addition
3. customThe cooling bath is removed
4. temperatureto warm to room temperature
5. customThe reaction is then quenched by the dropwise addition of water (9.5 mL)
6. additionby the addition of 2.5N NaOH (280 mL)
7. additionHydrogen peroxide (30% aqueous solution, 16 mL) is carefully added dropwise such that the reaction temperature
8. additionis about 45° C. upon completion of the addition
9. additionAn oil bath is added
10. temperaturethe reaction mixture maintained at 45°-50° C. for one hour
11. temperatureto cool
12. additiondiluted with 20% NaCl (500 mL)
13. customThe layers are separated
14. extractionthe aqueous layer extracted with an additional portion of tetrahydrofuran (300 mL)
15. washThe combined organic extracts are washed with 20% NaCl (500 mL)
16. dry with materialdried (MgSO4)
17. concentrationconcentrated

ORD record

ord-5c714b68d82448eaa54f55aa83c5c7f0

Source dataset

uspto-grants-1990_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04966907