Hydrochloric Acid → 2-Hydroxymethyl-chroman-4-one

The 3 g of 4-oxo-chromane-2-carboxylic acid in THF (65 mL) was stirred was cooled to 0° C. and borane-methyl sulfide complex (2.5 mL of M solution, 25 mmoles) was added dropwise for about 15 minutes. The solution was warmed to room temperature and then heated at reflux for 4 hours. The solution was cooled to room temperature and 10% aqueous hydrochloric acid (20 mL) was added over 15 minutes and the solution was stirred at room temperature for 2 hours. The mixture was concentrated to approximately 25 mL. The solution was poured into ethyl acetate (50 mL) and washed with water (2×30 mL), saturated sodium bicarbonate (2×30 mL) and saturated ammonium chloride (2×30 mL). The organic layer was separated dried over anhydrous MgSO4, and then concentrated in vacuo to yield about 2.6 g of 2-(hydroxymethyl)-chroman-4-one (86.7% yield)

1. temperatureThe solution was warmed to room temperature
2. temperatureheated
3. temperatureat reflux for 4 hours
4. temperatureThe solution was cooled to room temperature
5. concentrationThe mixture was concentrated to approximately 25 mL
6. additionThe solution was poured into ethyl acetate (50 mL)
7. washwashed with water (2×30 mL), saturated sodium bicarbonate (2×30 mL) and saturated ammonium chloride (2×30 mL)
8. customThe organic layer was separated
9. dry with materialdried over anhydrous MgSO4
10. concentrationconcentrated in vacuo

ORD-Eintrag

ord-e1b2f3182738448d9ff1217443bfb034

Quelldatensatz

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06756403B2