Synthesis of 3-(Trifluoromethyl)benzo[c][1,6]naphthyridines from Substituted 4H-Pyran-4-ones via 4-Amino-5-Aryl-2-(trifluoromethyl)pyridines

Synthesis of new fluorine-containing dihydrobenzo[c]acridines from trifluoroacetyl dihydronaphthalene and substituted anilines

“…To search for better reaction conditions, we tested some Lewis acids or basic conditions and that could be used for the synthesis of 5a. Thus, TiCl 4 [15], ZnCl 4 [16], P 2 O 5 /POCl 3 [17], POCl 3 [18] and PPA in ethanol, produced no positive results. The conditions used by Hojo et al [12] for the synthesis of the benzo[c]acridines and its dihydro derivative, which employed triethylamine (basic condition) and trifluoroacetic acid (acid conditions) have also failed.…”

Synthesis of 1,6‐Naphthyridine and Its Derivatives: A Systematic Review

“…Wibberly (1962) prepared 1,6-naphthyridine-5-one derivative (41) in two steps from the starting material, 2-(3-nitrostyryl)-6-phenylnicotinic acid (39) (Scheme 9). [27] Bromination of starting material facilitated the formation of intramolecular cyclization product, 7-(3-nitrophenyl)-2-phenyl-5H-pyrano [4,3b]pyridin-5-one (40). Aminolysis of this product afforded the desired product with a low (overall) yield.…”

2-(Trifluoromethyl)-4H-pyran-4-ones: Convenient, available and versatile building-blocks for regioselective syntheses of trifluoromethylated organic compounds

“…A c c e p t e d M a n u s c r i p t 15 Thus, despite 2-CF 3 -4-pyrones belong to a fairly young class of compounds and not so many representatives of them were presented in the literature, nevertheless, the described methods could be used for the preparation of many other CF 3 -pyrones. Reactions of 2-CF 3 -4-pyrones with nucleophiles can be classified as proceeding with the initial nucleophilic attack at carbons C-2, C-4 or C-6 (usually with the opening of the pyrone ring) or at the side chain (substituent), that is without opening of the pyrone ring.…”