6-Chloro-imidazo[1,2-a]pyrazine

compound 5-a (2.6g, 20mmol), 2- bromo-1, 1-diethoxyethane (12.0g, 60.89mmol) was dissolved in 30ml isopropanol was then added a solution of hydrogen bromide (10.5g, 62.22mmol), 80 deg. C stirred overnight. Completion of the reaction, cooled to room temperature, adjusted to pH 8 sodium hydrogen carbonate, extracted with dichloromethane, the combined organic phases separated, concentrated under reduced pressure to give a crude product which, by Combi-flash chromatography [DCM: MeOH = 90: 10 ~ 70: 30 ] to give a brown solid compound 16-b (2.3g), was used directly in the next reaction. Yield: 49.75percent, purity 96.63percent.To a solution of 5-chloropyrazin-2-amine (2.5 g, 19.3 mmol) in IPA (25 mL) was added 2-chloroacetaldehyde (5.68 g, 28.95 mmol). The resulting mixture was stirred at 100 °C for 16 hours to give a black suspension. The reaction solution was cooled to room temperature and concentrated to give a residue. The residue was dissolved in EtOAc (150 mL) and K2C03 aqueous (60 mL). After separatation, the organic layer was washed with brine (50 mL x 2), dried over anhydrous Na2504, filtered and concentrated to give a crude product. The crudeproduct was purified by silica gel column with EtOAc in PE = (10percent to 50percent) to give 6- chloroimidazo[1, 2-alpyrazine (1000 mg, 33percent yield) as a solid. ‘H NMR (400 MHz, CDC13) ö11 8.94 (s, 1H), 8.20 (s, 1H), 7.88 (s, 1H), 7.73 (s, 1H). LCMS R = 0.174 mm in 1.5 mm chromatography, MS ESI calcd. for C6H5C1N3 [M+H1 154.0, found 153.8.

Molecular Weight:153.57
XLogP3:1.7
Hydrogen Bond Acceptor Count:2
Exact Mass:153.0093748
Monoisotopic Mass:153.0093748
Topological Polar Surface Area:30.2
Heavy Atom Count:10
Complexity:130
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes