Phosphorus oxychloride → 3-(7-chlorothieno[2,3-d]pyridazin-2-yl)-N-cyclopropyl-4-methylbenzamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-methyl-3-(7-oxo-6,7-dihydrothieno[2,3-d]pyridazin-2-yl)benzoic acid (1.01 g, 3.53 mmol) and phosphorus oxychloride (30.0 ml, 322 mmol) was heated to 105° C. for 4 hrs. After cooling to RT, the volatiles were removed in vacuo. The residue was re-dissolved in DCM (50 ml) and treated with TEA (1.49 ml, 10.6 mmol) and dropwise with cyclopropylamine (0.746 ml, 10.6 mmol). The mixture was diluted with 1 M KHSO4 and extracted with CH2Cl2 (3×). The combined organics were dried over Na2SO4, filtered and concentrated over SiO2. Column chromatography (MeOH/CH2Cl2=0→2%) afforded the desired product. Yield: 0.92 g. MS (ESI, pos. ion) m/z: 344 (M+1).

Provenance & Evidence