Dimethyl Sulfoxide → 5-(4-Hydroxy-6-quinazolinyl)furan-2-carbaldehyde

Participants

Reaction Steps

A 5:2 v/v solvate mixture of Dimethyl sulfoxide (DMSO) and H2O (1400 mL) was degassed for 30 min at ambient temperature using nitrogen. Under an atmosphere of nitrogen, 5-formylfuran-2-ylboronic acid ((VIa); 26.8 g, 193 mmol) was added into this mixture and dissolved. [HP(t-Bu)3]BF4 (840 mg, 2.94 mmol) and palladium acetate (Pd(OAc)2, 680 mg, 2.94 mmol) was added and the mixture was stirred at ambient temperature for 20 min. Then, potassium acetate (AcOK, 18.8 g, 192 mmol) was added into the reactor and was stirred for 20 min. 6-Iodoquinazolin-4(3H)-one ((Va); 40 g, 147 mmol) was added. Then the reaction mixture was heated to 80±5° C. (internal temperature). Upon completion of the reaction (HPLC), the reaction mixture was hot-filtered, then hot water (400 mL, 80±5° C.) was added into the filtrate. This was slowly cooled to 0-15° C. (solid started to precipitate at 70° C. (internal temperature)) and was then filtered. The filter cake was washed with H2O (80 mL), then with MeCN (60 mL), and dried in vacuo at 60±5° C. for 6 h to provide 5-(4-oxo-3,4-dihydroquinazolin-6-yl)-furan-2-carbaldehyde ((IX); 34.6 g, 144 mmol) with 99.7% HPLC purity in 97.6% HPLC yield. 1H NMR (300 MHz, d6-DMSO): δ 7.47 (d, J=3.8 Hz, 1H), 7.69 (d, J=3.8 Hz, 1H), 7.77 (d, J =8.6 Hz, 1H), 8.17 (s, 1H), 8.27 (dd, J=8.6, 2.1 Hz, 1H), 8.52 (d, J=2.1 Hz, 1H), 9.66 (s, 1H); 13C NMR (75 MHz, CDCl3): δ 110.5, 122.6, 123.9, 126.0, 127.5, 129.0, 131.4, 147.1, 150.1, 152.7, 157.6, 161.2, 178.8; ESI-MS, Pos: [M+H]+m/z 241; IR (cm−1): 1713, 1671, 1604, 1462; m.p.: 267° C.

Provenance & Evidence