Hydrogen Bromide → HCID 178430682, compound

Participants

Reaction Steps

Bromoacetaldehyde diethyl acetal (12.2 mL, 81.4 mmol) and a solution of 48% HBr (0.94 mL) are heated at reflux for 1.5 hours, then poured into a suspension of NaHCO3 (1.92 g) in propan-2-ol (31.3 mL). The resulting solid is filtered off and 3-amino-5-methyl-pyrazin-2-ol (3.13 g, 25.0 mmol) is added. The solution is refluxed for 2 hours then left to stand overnight and the solid formed washed with IPA and ether. The solid is added to a solution of DCM (60 mL) and NaHCO3 sat. (30 mL), the two layers are separated and the aqueous phase is extracted with DCM. The combined organic layers are dried with MgSO4 anh., filtered and evaporated to give a brown solid product. The aqueous phase is again extracted with a CHCl3/IPA 9/1, dried with MgSO4 anh., filtered and concentrated to give a brown solid product. The IPA and Ether used previously for washing the solid are combined, evaporated and submitted to the same process described previously to give a brown solid quite impurified from the DCM extraction and a brown solid with the CHCl3/IPA of similar purity to the one obtained beforehand. The products resulting from the first DCM extraction and the two CHCl3/IPA extraction are combined and washed with cold MeOH to give 5-Methyl-imidazo[1,2-a]pyrazin-8-ol as a pale yellow solid (1.32 g) that is submitted into the next step without further purification.

Provenance & Evidence