Efficient Thiophene Synthesis Mediated by 1,3‐Bis(carboxymethyl)imidazolium Chloride: C‐C and C‐S Bond Formation

Abstract

Supporting information for this article is given via a link at the end of the document.

1,3-Bis(3-carboxypropyl)-1H-imidazole

“…The resultant brownish precipitate was filtered and washed using cold diethyl ether (10 mL) to obtain a tan solid (2.1 g, 87% yield). IR (ATR): ν 3132, 3105, 2981 (COO-H, st), 2862 (C-H, st), 1709, 1666 (C=O, st), 1562 [(COO) -, st as], 1404 [(COO) -, st si] cm −1 ; 1 H-NMR (300 MHz, D 2 O): δ H 8.85 (s, 1H, NCHN-imidazole ring, 7.54 (d, J = 1.6 Hz, 2H, NCHCH-imidazole ring), 4.26 (t, J = 7.1 Hz, 4H, 2 × NCH 2 ), 2.35 (t, J = 7.2 Hz, 4H, 2 × CH 2 CO 2 ), 2.17 (m, 4H, 2 × CH 2 ) ppm; 13 C-NMR (75 MHz, D 2 O): δ C 179.0 (CO 2 ), 135.5 (NCN-imidazole ring), 122.5 (NCCN-imidazole ring), 48.9 (NCH 2 ), 32.0 (CH 2 CO 2 ), 25.4 (NCH 2 CH 2 ) ppm; LRMS (DIP-EI): m/z 240 (M + , 0.3%), 156 (21), 155 (56), 154 (68), 138 (13), 137 (42), 135 (64), 110 (12), 109 (22), 108 (22), 107 (16), 96 (21), 95 (50), 94 (13), 87 (13), 86 (23), 83 (39), 82 (100), 81 (83), 80 (28), 69 (19), 68 (28), 67 (12), 56 (19), 55 (28), 54 (31), 53 (18), 52 (11), 45 (16), 43 (20), 42 (54), 41 (44), 40 (17).…”

“…Our research group has optimized the preparation of the 1,3-bis(carboxymethyl)imidazole (bcmim) starting from glycine, glyoxal, and formaldehyde, and the transformation of bcmim in the corresponding halide salts [14]. This type of biscarboxy-imidazole derivatives has been useful as a precursor for the preparation of efficient and selective catalysts for sustainable organic transformations [14][15][16][17][18][19].…”

Ionic Organic Solid 1,3-Bis(sulfomethyl)imidazoliumate as an Effective Metal-Free Catalyst for Sustainable Organic Syntheses

“…These imidazolic compounds constitute great heterogeneous catalysts due to their substantial Brønsted acidity [ 27 ], negligible solubility in aprotic and certain protic organic solvents [ 25 ], and high robustness [ 28 ]. Indeed, 1,3-bis(carboxymethyl)imidazolium chloride (bcmimCl) has been effectively applied as a promoter to a variety of synthetic protocols, including the preparation of quinolines and acridines via Friedländer reaction [ 25 ], the synthesis of dihydropyrimidones by the multicomponent Biginelli reaction [ 29 ], the obtention of 2,4-diarylthiophenes [ 30 ], and the allylation of anilines with allylic alcohols [ 28 , 31 ]. The latter is particularly interesting, as the regioselectivity of the process is controlled by the counter-anion of the imidazolium salt.…”