3-Thiophenecarboxaldehyde → HCID 123554834, compound

Participants

Reaction Steps

To a suspension in DMSO/THF 1:1 volume/volume (26 mL) of 3-thiophencarboxaldehyde (2.0 g; 18 mmoles) and 2-(carboxyethyl) (triphenyl)phosphonium bromide (8.9 g; 21 mmoles) 5.3 g of potassium t-butoxide are added. The reaction mixture is left under stirring for 2 hours at room temperature. Then the organic phase is washed with water (20 mL) and extracted with chloroform (2×20 mL). The solvent is removed and the aqueous phase is acidified with concentrated HCl and extracted with chloroform (2×20 mL). The organic phase is recovered and washed with water and dried with sodium sulphate. After filtration, the organic phase is concentrated under vacuum. The obtained residue is purified by chromatography on silica gel by using as eluent a ligroin/ethyl acetate 1:1 volume/volume mixture. 2.3 g of a mixture of the two cis and trans diastereoisomers of the 5-(thiophen-3-il)-pent-4-enoic acid are obtained (yield 70%). Rf=0.35 (ligroin/ethyl acetate 6/4 volume/volume); 1H NMR (CDCl3) δ (ppm): 7.29 (m, 1H, ArH), 7.23 (m, 1H, ArH), 7.18 (m, 2H, ArH), 7.09 (m, 2H, ArH), 6.44 (m, 2H, CH), 6.06 (m, 1H, CH), 5.57 (m, 2H, CH), 2.68 (m, 2H, CH2), 2.52 (m, 6H, CH2); 13C NMR (CDCl3) δ (ppm): 179.2, 179.1, 139.9, 138.2, 128.9, 128.5, 127.9, 125.9, 125.5, 125.2, 124.9, 124.5, 123.1, 121.2, 33.9, 33.8, 27.8, 24.2; FT-IR (film) νmax: 3098.1, 2923.5, 1693.2, 1410.6, 1267.7, 1242.6, 1206.6, 1155.3, 966.1, 755.4 cm−1.

Provenance & Evidence