UDC 4,12,[4][5]6]pyrimido [l,2-b]benzo [d,e]isoquinoline-4,12-dione and its 8-nitro-and 8-amino-substituted derivatives were obtained starting from 4-amino-3-carbamoyl-l-methylpyrazole and naphthalic and 4-nitronaphthalic anhydrides.
The spectral properties of the synthesized compounds were studied.
The products of monoacylation of 3,4-diamino-l,5-dimethyl-and 4,5-diamino-l-methylpyrazole with 4-nitronaphthalic anhydride do not undergo cyclization to pyrazole analogs of naphthoylenebenzimidazole [i]. However, the synthesis of 3-methyl-3,4,12,13H-pyrazolo[5',4'-5,6]pyrimido[i,2-b]benzo [d,e]isoquinoline-4,12-dione (I) and its 8-nitro and 8-amino derivatives on the basis of 4-amino-5-carbamoyl-l-methylpyrazole demonstrated the possibility of heterocyclization with the formation of a pyrimidinone ring [2], as in the case of 5,13,14Hbenzo [d,e]isoquinolino[2',3']quinazoline-5,13-dione [3].
In order to study the effect o~ the nature of the ring annelated to the pyrimidine fragment on the spectral properties of such compounds we synthesized the isomeric (with respect to
, as well as some of its derivatives that contain a strong electron-acceptor (Vb) or electron-donor (Vc) substituent, starting from 4-amino-3-carbamoyl-l-methyipyrazole (II) and naphthalic and 4-nitronaphthalic anhydride (IIIa, b).
*See [i] for Communication 8.