Reaktion #9616

Reaktionsgleichung

4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoic acid

2,2-dimethoxypropane

HCl

→

methyl 4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoate

Lösungsmittel

methanol

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe mixture was concentrated under reduced pressure
2. 2
   workup.ADDITIONToluene (2×60 mL) was added
3. 3
   Einengenthe mixture concentrated again (2×)

Vorschrift

To a solution of 4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoic acid (8.33 g, 29.2 mmol) and 2,2-dimethoxypropane (3.95 g, 37.9 mmol) in methanol (100 mL) was added 1 M HCl in dioxane (2.0 mL). The reaction mixture was stirred at 50° C. for 22 h. The mixture was concentrated under reduced pressure. Toluene (2×60 mL) was added and the mixture concentrated again (2×) to afford methyl 4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoate as an off-white, semi-solid (8.60 g, 99%). This material was used in the next step without further purification. LC-MS: ret. time 3.23 min; m/z 298.8 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.34 (s, 6H), 3.28 (s, 2H), 3.67 (s,3H), 7.58 (d, 2H), 7.78 (d, 2H).

Quelle