Phosphoric Acid → HCID 12224156, compound

Participants

Reaction Conditions

Reaction Steps

97.6 g (0.5 mol) of phenanthridone, 60 g (0.55 mol) of o-phenylenediamine and 15 g of 85% strength H3PO4 (remainder water) are mixed and fused under nitrogen. The elimination of H2O starts from 200° C. The temperature is gradually raised to 300° C over the course of 6 hours, whilst stirring, and is additionally kept at 300° to 330° C for 8 hours. In the course of this time, about 12 g of H2O have distilled over. A fractional distillation in an oil pump vacuum is then carried out and 77 g (57.5% of theory) of benzimidazo-[1,2-f]-phenanthridine of boiling point 227° C/0.4 mm Hg and melting point 135° C are obtained as almost colourless crystals (after recrystallisation from 5 parts of ethanol). ##STR31##

Provenance & Evidence