Em. Awad et al., Synthesis and reactivity of 2-(6,7-diethoxy-3,4-dihydroisoquinolin-1-yl) acetonitrile towards hydrazonoyl halides, HELV CHIM A, 84(5), 2001, pp. 1172-1180
The synthesis of 2-(6,7-diethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile (
1) has been performed by ring closure of the corresponding amide according
to the Bischler-Napieralski method (Scheme 1). Based on spectroscopic data,
the tautomeric 2-(tetrahydroisoquinolin-1-ylidene)acetonitrile is the actu
al compound. The reactions of 1 with alpha -oxohydrazonoyl halides 4 in the
presence of Et3N led to 2-(aryldiazenyl)pyrrolo[2,1-a]-isoquinoline deriva
tives 8 (Scheme 2), whereas with C-(ethoxycarbonyl)hydrazonoyl chlorides 14
, 2-(arylhydrazono)pyrrolo[2,1-a]isoquinoline-l-car 16 were formed (Scheme
4). The structures of the products were established from their analytical a
nd spectroscopic data and, in the case of 8b, by X-ray crystallography.