Studies in the fluoranthene series

Abstract

1. The mixture of acids obtained on the oxidation of 4:11 -dibromofluoranthene has been shown to consist of 2:7- dibromofluorenone -l- carboxylic acid and 6- bromofluorenone -l- carboxylic acid. The structure of the latter was proved by its decarboxylation to 3- bromofluorenone.2. The action of diazomethane on fluorenone acids in presence of methanol has been investigated.. The ring enlargement to substituted 9- phenanthrols, noted by previous workers, has been confirmed.3. The reduction of 4:11 -dibromofluoranthene to 1:2:3:4 - tetrahydrofluoranthene has been accomplished.4. The synthesis of 4:11 -dicarboxyfluoranthene from 4:11 -dibromofluoranthene was successfully accomplished. This di -acid was shown to be different from that obtained during Friedel- Crafts reaction on fluoranthene.5. The tribromofluoranthene, obtained on the bromination of 4:11 -dibromofluoranthene, has been shown, both by degradation and by synthesis, to be 4:11:12-tribromofluoranthene.6. 4:5- Dibromophthalic acid was prepared by the oxidation of 4:5- dibromo -o- xylene and shown to be identical with one of the oxidation products of 4:11:12- tribromofluoranthene, thereby proving the structure of the latter,7. The nitration of 1:2:3:4 -tetrahydrofluoranthene gave two products, which were shown to be 1- hydroxy -2- nitro- 1:2:3:4 -tetrahydrofluoranthene and its dehydration product, 2- nitro- 3:4- dihydrofluoranthene.8. The dehydrogenation of 2- nitro -3:4- dihydrofluoranthene to 2- nitrofluoranthene has made easily accessible fluoranthene compounds substituted in the 2- position. which are otherwise difficult to obtain.9. The nitration of 5- bromo- 1:2:3:4- tetrahydrofluoranthene also gave two products which are the bromo-analogue6 of those obtained in the nitration of 1:2:3:4 - tetrahydrofluoranthene.10. The synthesis of 1:2- benzfluorene has been accomplished, starting from ß - 1- fluorenonepropionío acid.