tert-butyl 5,6-dihydroimidazo[1,2-a]pyrazine-7(8H)-carboxylate

345311-02-6

345311-03-7

The general procedure for the synthesis of 7-Boc-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine from the compound (CAS: 345311-02-6) is as follows: to a solution of N-(2-chloroethyl)-N-(1-{[2-(trimethylmethylsilyl)ethoxy]methyl}-1H-imidazol-2-ylmethyl)carbamate (description 162, 2.52 g, 2.5 mmol. 6.5 mmol) to a solution of tetrahydrofuran (50 mL) was added tetrabutylammonium fluoride (1M solution of tetrahydrofuran, 7.1 mL, 7.1 mmol) and the reaction mixture was heated to reflux for 1.5 hours. Subsequently, tetrabutylammonium fluoride (1M tetrahydrofuran solution, 7.1 mL, 7.1 mmol) was added again and the reaction mixture was continued to be heated to reflux for 20 hours. After completion of the reaction, the mixture was cooled and the solvent was removed by evaporation under reduced pressure. The residue was purified by silica gel fast column chromatography using CH2Cl2/MeOH (97:3) as eluent to give 7-Boc-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine (505 mg, 35% yield). Mass spectrum (electrospray positive ion mode) m/z: 224 ([M+1]+).