Toluene → 4,6-Dichloroquinazoline

Participants

Reaction Steps

Preparation D1, Step 2: 6-Chloroquinazolin-4-ol (400 mg, 2.21 mmol, 1 eq.), phosphorus oxychloride (1.99 mL, 21.4 mmol, 9.64 eq.) and triethylamine (0.99 mL, 7.11 mmol, 3.21 eq.) were mixed at room temperature under nitrogen and then refluxed for 2.5 hours. Worked up by stripping the reaction, then re-rotovapping the residue 2 times from toluene to obtain brown solids. Methylene chloride (25 mL) was added to dissolve the solids. The organic mixture was then rinsed 2 times with saturated ammonium chloride (25 mL). The organic layer was dried (sodium sulfate) and stripped to give brown solids. The solids were purified over silica gel in 9:1 to 3:1 hexanes/ethyl acetate. Obtained 4,6-dichloroquinazoline (300 mg) as an off-white solid. Yield=68%. 1H NMR (400 MHz) (DMSO-D6) δ 9.16 (s, 1H): 8.33 (s, 1H), 8.17 (apparent t, 2H, J=7 Hz).

Provenance & Evidence