ChemicalBook CAS DataBase List alpha-Cyclopentylmandelic acid

alpha-Cyclopentylmandelic acid synthesis

7synthesis methods

Product Name:alpha-Cyclopentylmandelic acid
CAS Number:427-49-6
Molecular formula:C13H16O3
Molecular Weight:220.27

611-73-4 Synthesis

611-73-4
303 suppliers
$36.00/5g

33240-34-5
187 suppliers
$88.00/100g

427-49-6
318 suppliers
$6.00/1g

Yield:427-49-6 36.4%

Reaction Conditions:

in diethyl ether at 0 - 20; for 24.5 h;

Steps:

Cyclopentylmagnesium bromide ether solution (100 ml, 2M; 0.2 mol) was added drop-wise to benzoylformic acid (15 g, 0.1 mol) in 330 ml of anhydrous ethyl ether at 0° C. The mixture was stirred at 0° C. for 30 min and at room temperature for 24 h. The reaction mixture was treated with 1 N HCl, and the aqueous solution was extracted with ether. The combined ether solution was treated with K₂CO₃solution. The potassium carbonate solution was acidified with HCl and extracted with ether twice. The ether solution was dried with anhydrous sodium sulfate and evaporated to give a crude product. The crude product was washed with water to get pure racemic cyclopentylmandelic acid 1 (8.0 g, 36.4%). Needle-like crystal, m.p.: 153-154° C. ¹H NMR (CDCl₃,300 MHz): 1.28-1.39, 1.42-1.50, 1.51-1.61, 1.63-1.72 [8H, m, (CH₂)₄], 2.93 [1H, p, CHC(OH)], 7.26-7.30, 7.33-7.36, 7.65-7.67(5H, m, Ph) ppm.; Cyclopentylmagnesium bromide ether solution (100 ml, 2M; 0.2 mol) was added drop-wise to benzoylformic acid (15 g, 0.1 mol) in 330 ml of anhydrous ethyl ether at 0° C. The mixture was stirred at 0° C. for 30 min and at room temperature for 24 h. The reaction mixture was treated with 1 N HCl, and the aqueous solution was extracted with ether. The combined ether solution was treated with K₂CO₃solution. The potassium carbonate solution was acidified with HCl and extracted with ether twice. The ether solution was dried with anhydrous sodium sulfate and evaporated to give a crude product. The crude product was washed with water to get pure racemic cyclopentylmandelic acid 1 (8.0 g, 36.4%). Needle-like crystals, m.p.: 153-154° C. ¹H NMR (CDCl₃, 500 MHz): 1.28-1.39, 1.42-1.50, 1.51-1.61, 1.63-1.72 [8H, m, (CH₂)₄], 2.93 [1H, p, CHC(OH)], 7.26-7.30, 7.33-7.36, 7.65-7.67(5H, m, Ph) ppm.