ethyl 2-(3-hydroxyphenoxy)-2-methylpropanoate synthesis

Yield:328919-24-0 72%

Reaction Conditions:

Stage #1: recorcinolwith ethanol;sodium for 1 h;Heating / reflux;
Stage #2: ethyl 2-bromoisobutyrate in ethanol; for 3 h;Heating / reflux;
Stage #3: with water;acetic acid

Steps:

10.b

b) Ethyl 2-(3-hydroxy-phenoxy)-2-methyl-propionate (10b); 15 g of resorcinol (136 mmol) are added to 120 ml of a solution of sodium (6.3 g, 274 mmol) in ethanol. The mixture is placed at reflux for 1 h then a solution of ethyl bromoisobutyrate (13.2 ml, 90 mmol) in 30 ml of ethanol is added dropwise. Heating is maintained for 3 h then the reaction medium is dry concentrated. The residue obtained is taken up in a solution of water and acetic acid then extracted with AcOEt. The organic phases are washed with water, dried on MgSO₄, then dry concentrated. The residue obtained is purified by flash chromatography on silica (CH₂Cl₂:AcOEt 90:10). 14.4 g of oil corresponding to intermediate 10b are thus isolated (72% yield). TLC silica gel 60 F 254 Merck, CH₂Cl₂:AcOEt 70:30, Rf=0.66.

References:

US2008/167313,2008,A1 Location in patent:Page/Page column 15