6-Chloro-iMidazo[1,2-b]pyridazine-3-carboxylic acid ethyl ester

Uses

6-Chloro-iMidazo[1,2-b]pyridazine-3-carboxylic acid ethyl ester is mainly used as pharmaceutical intermediates.

Synthesis

General procedure for the synthesis of ethyl 6-chloroimidazo[1,2-B]pyridazine-3-carboxylate from the compound (CAS:1150566-26-9): S-chloro-β-dimethylamino-methyleneamino-J-isoethyloxycarbonylmethyl-pyridazine-1-bromide (11.40 g, 32.40 mmol) was dissolved in acetonitrile (200 mL), followed by addition of diisopropylethylamine (15.22 mL, 64.81 mmol). The reaction mixture was stirred at room temperature for 4 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure and the residue was ground with water to afford 5.77 g of ethyl 6-chloroimidazo[1,2-b]pyridazine-3-carboxylate as a light brown solid in 77% yield. The product was characterized by 1H NMR (300 MHz, CDCl3): δ 8.36 (1H, s), 8.01 (1H, d, J = 9.4 Hz), 7.27 (1H, d, J = 9.4 Hz), 4.46 (2H, q, J = 7.1 Hz), 1.37 (3H, t, J = 7.1 Hz).LCMS analysis showed m/z 226 [M + 1]+ (molecular weight: 225.64).

References

[1] Patent: WO2009/60197, 2009, A1. Location in patent: Page/Page column 59
[2] Patent: US2012/65184, 2012, A1. Location in patent: Page/Page column 37