Hydrochloric Acid → HCID 69029202, Verbindung

Temperatur

-30 °C

A solution of 20% lithiumhexamethyldisilazane in tetrahydrofuran (217.5 mL, 260 mmol) was added to a well-stirred solution of 2,4-dihydroxy acetophenone, 14 (9.88 g, 65 mmol) in tetrahydrofuran (150 mL) under nitrogen atmosphere at −78° C. for 30 min. The reaction mixture was stirred at −78° C. for 1 h and at −30° C. for 2 h. It was again cooled to −78° C. and a solution of ethyl-3,5-dibenzyloxy-benzoate 8 (23.5 g, 65 mmol) in tetrahydrofuran (100 mL) was added over a period of 30 min. It was further stirred at room temperature for overnight and poured into ice water containing hydrochloric acid. It was extracted with chloroform, dried over sodium sulphate, filtered and evaporated on rotavapor to afford 1-(3,5-bis-benzyloxy-phenyl)-3-(2,4-dihydroxy-phenyl)-propane-1,3-dione (16). The residue, 16 (37.8 g) was refluxed with Dowex-H+ (8 g) in 2-propanol (300 mL) for 3-4 h. 2-Propanol was evaporated on rotavapor, residue suspended in hot dimethyl formamide and filtered. The filtrate was concentrated under reduced pressure and the product was washed with cooled methanol (3*200 mL) to afford 22. Yield 23.8 g (81%); mp 248-249° C.; MS (FAB) 451 (M++1); IR (KBr) 3452, 1620; 1H NMR (200 MHz, DMSO-d6) δ 7.84 (d, J=8.7 Hz, 1H), 7.52-7.28 (m, 10H), 7.23 (d, J=1.9 Hz, 2H), 6.98 (d, J=2.0 Hz, 1H), 6.89 (s, 1H), 6.89 (dd, J=8.6 Hz, 2.1 Hz, 1H), 6.82 (s, 1H), 5.14 (s, 4H).

1. temperatureIt was again cooled to −78° C.
2. stirringIt was further stirred at room temperature for overnight
3. extractionIt was extracted with chloroform
4. dry with materialdried over sodium sulphate
5. filtrationfiltered
6. customevaporated on rotavapor

ORD-Eintrag

ord-5d32bb3ee978431695101b4c755354a1

Quelldatensatz

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07635779B2