Dichloromethane → HCID 59633050, compound

Participants

Reaction Steps

To a stirred solution of 1-(5-bromothiophen-2-yl)-3-dimethylaminopropenone (0.70 g, 2.7 mmol) in EtOH (15 mL) was added methylhydrazine (0.16 mL, 3.0 mmol) and then acetic acid (0.45 mL, 8.0 mmol). The resulting mixture was heated at reflux for 2 h, allowed to cool to ambient temperature and then concentrated under reduced pressure. The residue was diluted with DCM (50 mL), washed with H2O and brine, then dried (Na2SO4), concentrated and purified by chromatography (silica, DCM) to yield the title compound 10a (0.21 g) as a white solid and regioisomer, 5-(5-bromothiophen-2-yl)-1-methyl-1H-pyrazole, 11a (035 g) as a pale yellow solid. 10a: Rf 0.42 (DCM); 1H-NMR (CD2Cl2): δ 7.36 (1H, d), 7.01 (2H, m), 6.41 (1H, d), 3.87 (3H, s); 11a: Rf 0.19 (DCM); 1H-NMR (CD2Cl2): δ 7.42 (1H, d), 7.10 (1H, d), 6.94 (1H, m), 6.36 (1H, d), 3.92 (3H, s).

Provenance & Evidence