Reaktion #9643

Reaktionsgleichung

trans-2-(4-bromobenzoyl)cyclopentanecarboxylic acid

2,2-dimethoxypropane

HCl

→

methyl trans-2-(4-bromobenzoyl)cyclopentanecarboxylate

Ausbeute 83.2%

Lösungsmittel

MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeevaporated to dryness
2. 2
   SonstigeThe resulting residue was purified by flash chromatography (Biotage Flash 40M)

Vorschrift

To a solution of trans-2-(4-bromobenzoyl)cyclopentanecarboxylic acid (2.0 g, 6.26 mmol) in MeOH (70 mL) was added 2,2-dimethoxypropane (1.63 g, 15.65 mmol) and HCl (4.0 M in dioxane) (1.0 mL). The resulting solution was stirred at 40° C. overnight and then evaporated to dryness. The resulting residue was purified by flash chromatography (Biotage Flash 40M) using 7 to 11% ethyl acetate in hexanes to afford methyl trans-2-(4-bromobenzoyl)cyclopentanecarboxylate (1.62 g, 83%). 1H NMR (400 MHz, CD2Cl2) δ 1.70–1.95 (m, 4H), 2.08–2.21 (m, 2H), 3.40 (m, 1H), 3.64 (s, 3H), 4.04 (m, 1H), 7.64 (m, 2H), 7.86 (m, 2H).

Quelle