Formaldehyde → 5-(Benzyloxy)-4-bromo-2-hydroxybenzaldehyde

Temperatur

72 °C

To a chilled solution of phenol (Step 1) (4.7 g, 16.8 mmole) in ACN was added MgCl2 (1.92 g, 20 mmole) portion-wise while maintaining the temperature below 10° C., followed by paraformaldehyde (2.52 g, 84 mmole) and TEA (9.5 mL, 67 mmole) producing a 15° C. exotherm. The mixture was heated to 72° C. for 2 hrs. The reaction was cooled to room temperature and poured into saturated aqueous ammonium chloride (500 mL), extracted with ethyl acetate (2×150 mL). The combined organic phases were washed with aqueous NaHCO3 solution (2×150 mL), aqueous 1N HCl solution (2×150 mL), and brine (2×150 mL), dried over Na2SO4, filtered and concentrated in vacuo. The crude material was subjected to flash chromatography (Silica, 5% ethyl acetate/hexane). ESLRMS m/z 306.9 (M+H).

1. temperaturewhile maintaining the temperature below 10° C.
2. customproducing a 15° C. exotherm
3. temperatureThe reaction was cooled to room temperature
4. extractionextracted with ethyl acetate (2×150 mL)
5. washThe combined organic phases were washed with aqueous NaHCO3 solution (2×150 mL), aqueous 1N HCl solution (2×150 mL), and brine (2×150 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo

ORD-Eintrag

ord-21ca91ec70114f2bad72bbb7ec60b667

Quelldatensatz

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07259266B2