Triethylsilane → Methyl 3-[(quinolin-4-ylmethyl)amino]thiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-amino-thiophene-2-carboxylic acid methyl ester (5 g, 31.8 mmol) and 4-quinoline-carboxaldehyde (5.25 g, 33.4 mmol) in TFA/CH2Cl2 (75 mL, 75 mL) was heated at 50° C. for 3.5 h. The solution was cooled in an ice bath and triethylsilane (10.2 mL, 63.6 mmol) was added drop-wise over 5 min. The reaction mixture was stirred at 50° C. for 3.5 h, cooled to rt, and 500 mL of CH2Cl2 was added. The reaction mixture was basified with 10N NaOH (pH 6-7) followed by sat. NaHCO3 (pH 8). The CH2Cl2 layer was separated and the aqueous layer was extracted with CH2Cl2 (2×10 mL). The organic extracts were combined, washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to yield the crude product, which was triturated with hexane to give pure methyl 3-[(quinolin-4-ylmethyl)amino]thiophene-2-carboxylate as white solid. MS (ES): m/z 298.55 (100) [MH+]; 1H-NMR (400 MHz/CDCl3): δ 3.87 (s, 3H), 5.00 (d, J=4.0 Hz, 2H), 6.48 (d, J=5.6 Hz, 1H), 7.30 (d, J=5.6 Hz, 1H), 7.36 (m, 1H), 7.41 (d, J=4.4 Hz, 1H), 7.62 (t, J=8.0 Hz, 1H), 7.76 (t, J=9.6 Hz, 1H), 8.01 (d, J=8.0 Hz, 1H), 8.17 (d, J=8.4 Hz, 1H), 8.86 (d, J=4.4 Hz, 1H).

Provenance & Evidence