ChemInform Abstract: The Synthesis of Pyrrolo(1,2‐a)pyrazin‐1(2H)‐ones and Pyrrolo(1,2‐b) pyridazin‐6(5H)‐ones.

Abstract

The Synthesis of Pyrrolo(1,2-a)pyrazin-1(2H)-ones and Pyrrolo(1,2b) pyridazin-6(5H)-ones.-Condensation reaction of the methoxymethylpyrazines (I) with α-bromo ketones, e.g. (II), in aqueous sodium bicarbonate solution yields the methoxypyrrolopyrazines (III), together with small amounts of the desired pyrrolopyrazinones (IV). The reaction proceeds via quaternization of the pyrazine nitrogen followed by cyclization. The compounds (IV) are also obtained upon acidic hydrolysis of (III). Furthermore, quaternization-cyclization of the pyridazine (V) with (II) and subsequent hydrolysis of the methoxypyrrolopyridazine (VI) gives the target pyridazinone (VII). -(MCHATTIE, D.; BUCHAN, R.; FRASER, M.; LIN, P. V. S. K.