Water → HCID 22221610, compound

Participants

Reaction Steps

Compound 24 (0.6 g, 2.2 mmol) in DMF (3-5 mL) and hydrazine monohydrate (0.25 mL, 5 mmol) was treated with EDCl (1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) (0.64 g, 3.3 mmol) and the reaction allowed to stir at rt for several hours. The reaction was worked up by adding water and extracting twice with EtOAc. The combined EtOAc extracts were washed with brine and dried over MgSO4. The EtOAc was concentrated to render 125 mg of the crude acyl hydrazide which was used as is for the next step. The crude acyl hydrazide from the previous step was treated with 3-5 mL of triethyl orthoformate and catalytic p-toluenesulfonic acid and heated to reflux for 30 minutes. The reaction mixture was allowed to cool to rt and was poured into 2 N HCl aq, extracted with EtOAc, washed with 2 N HCl aq, saturated NaHCO3 aq, brine, and dried over MgSO4. Filtration and concentration followed by chromatography on silica gel (1:19 MeOH/CH2Cl2) gave 15 mgs of 138: MP=260-266° C.; 1H NMR (DMSO-d6) δ 9.94 (br s, 1 H), 9.75 (br s, 1 H), 9.45 (s, 1 H), 7.79 (d, 2 H, J=8.7 Hz), 7.33 (d, 1 H, J=2.4 Hz), 7.20 (s, 1 H), 7.18 (d, 1 H, J=2.4 Hz), 6.92 (d, 2 H, J=8.7 Hz); MS 295 (M+H)+.

Provenance & Evidence