Efficient modified von Niementowski synthesis of novel derivatives of 5a,14b,15-triazabenzo[a]indeno[1,2-c]anthracen-5-one from indolo[1,2-c]quinazoline

Starting from 2-(2-aminophenyl)indole novel triazabenzo[a]indeno[1,2-c]anthracen-5-ones could be reached in three steps through a modified von Niementowski reaction, which involves condensation of anthranilic acids with an S-alkylated 6-mercaptoindolo[1,2-c]quinazoline. Microwave irradiation in dry media was used in order to improve reactions where conventional heating was limited.