Potassium Carbonate → Cyclohexylmethyl 5-chlorothiophene-2-carboxylate

反応式

[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][CH:3]=1.[CH:10]1([CH2:16]Br)[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1.C(=O)([O-])[O-].[K+].[K+]>O>[Cl:1][C:2]1[S:6][C:5]([C:7]([O:9][CH2:16][CH:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]2)=[O:8])=[CH:4][CH:3]=1

参加物

実験手順

A mixture of 5-chlorothiophene-2-carboxylic acid (3.01 g, 19.0 mmol), cyclohexylmethyl bromide (3.51 g, 19.8 mmol) and potassium carbonate (2.81 g, 20.33 mmol) was stirred under Ar at +85° C. for 3 days and cooled to room temperature. Reaction mixture was diluted with water and extracted with hexanes three times. Combined organic layers were dried over anhydrous MgSO4 and concentrated under reduced pressure. Purification by flash chromatography (2%-15% EtOAc—hexanes gradient) gave cyclohexylmethyl 5-chlorothiophene-2-carboxylate as a colorless oil. Yield (4.76 g, 97%); 1H NMR (400 MHz, CDCl3) δ 7.56-7.60 (m, 1H), 6.90-6.94 (m, 1H), 4.08 (d, J=6.10 Hz, 2H), 1.64-1.82 (m, 6H), 1.10-1.34 (m, 3H), 0.97-1.10 (m, 2H).