Water → HCID 57750763, compound
Reaction equation
[CH3:1][O:2][C:3](=[O:13])[CH2:4][C:5]1[S:6][CH:7]=[C:8]([CH2:10]OC)[CH:9]=1.B(Cl)(Cl)[Cl:15].O>ClCCl>[CH3:1][O:2][C:3](=[O:13])[CH2:4][C:5]1[S:6][CH:7]=[C:8]([CH2:10][Cl:15])[CH:9]=1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of (4-methoxymethyl-thiophen-2-yl)-acetic acid methyl ester (0.70 g, 3.50 mmol) in dichloromethane (20 mL) is treated with boron trichloride (3.50 mL, 1.0 M, 3.50 mmol) in a dropwise maner. After stirring at room temperature for 30 min the mixture is poured into water and extracted with dichloromethane (3×). The combined organic layers are washed with saturated aq NaCl, dried over Na2SO4, filtered and concentrated in vacuo. The resulting residue is purified by chromatography (silica gel, 5-10% ethyl acetate in heptane) to give (4-chloromethyl-thiophen-2-yl)-acetic acid methyl ester (0.58 g, 81%) as a colorless oil: 1H NMR (CDCl3, 300 MHz) δ 7.18 (s, 1 H), 6.95 (s, 1 H), 4.52 (s, 2 H), 3.80 (s, 2 H), 3.72 (s, 3 H).