Acetone → 1-Chloro-4-methyl-6-(prop-2-ynyloxy)phthalazine

Participants

Reaction Conditions

Reaction Steps

The mixture of 1-chloro-6-hydroxy-4-methylphthalazine (8) (195 mg, 1.00 mmol), 80% propargyl bromide (1.30 mmol) in toluene (145 μL), K2CO3 (187 mg, 1.35 mmol), and acetone (8 mL) is stirred at 68° C. under argon for 23 h, and then cooled to room temperature. The mixture is concentrated, diluted with H2O (40 mL), and extracted with ethyl acetate (70 mL and 60 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is purified on silica gel (33% to 56% ethyl acetate/hexane) to give 102 mg (44%) of 11 as alight-yellow solid, mp 178-180° C. IR 2946, 1615, 1378, 1234 cm−1; 1H NMR (DMSO-d6) δ 2.61 (t, J=2.1 Hz, 1H, CH≡C), 2.93 (s, 3H, CH3), 4.91 (d, J=2.1 Hz, 1H, CH≡CCH2), 7.40 (d, J=2.4 Hz, 1H, 5-PhthH), 7.58 (dd, J=9.1, 2.4 Hz, 1H, 7-PhthH), 8.23 ppm (d, J=9.1 Hz, 1H, 8-PhthH).

Provenance & Evidence