Quinolines 1.4- dihydro-2-hydroxy

Friedlander synthesis, 2, 445 Quinoline, alkenyl-1,2-dihydro-disproportionation, 2, 369 Quinoline, 2-alkoxy-reactions, 2, 351 Quinoline, 4-alkoxy-reactions, 2, 351 Quinoline, 2-alkoxy-4-hydroxy-synthesis... 

Quinolin-2-one, 3-cyano-4-hydroxy-synthesis, 2, 428 Quinolin-2-one, 3,4-dialkyl-Knorr synthesis, 2, 425 Quinolin-2-one, dihydro-Camps synthesis, 2, 418 synthesis, 2, 402 from benzazepinones, 2, 506 from indanone oxime, 2, 487 from indanones, 2, 488 by intramolecular Friedel-Crafts reactions, 2, 421... 

Reaction of 2,3-dihydro-3-hydroxy-3-methyl- 240 (R = Me), or a mixture of 2,3-dihydro-3-hydroxy-3-aryl-57/-pyrido[l,2,3-dfe]-l,4-benzoxazin-5-ones 240 (R = Ar) and (8-aroylmethoxy)quinolin-2(l//)-ones 241 (R = Ar) with ethyl 2-(bromomethyl)acrylate in the presence of activated Zn and hydroquinone gave 8-[(2,3,4,5-tetrahydro-4-methylidene-5-oxo-2-furanyl)-methoxy]quinolin-2(l//)-ones (242) (97HCA1161). 6,7-Dihydro derivatives of 240 reacted similarly (00HCA349). 

A mixture of 26 parts of 3-carbethoxy-6,7-methylenedioxy-4-hydroxy-quinoline, 16 parts of sodium hydroxide and 50 parts of dimethylformamide is heated at 70° to 75°C for 2 hours, then 31 parts of ethyl iodide is added over 1 hour with continued heating and stirring. After an additional 3 to 4 hours of heating (at 70° to 75°C) and stirring, the mixture is diluted with 500 parts of water, refluxed for 3 to 4 hours, acidified with concentrated hydrochloric acid and filtered to yield 18 to 22 parts of 1-ethyl-1,4-dihydro-6,7-methylene-dioxy-4-oxo-3-quinoline-carboxylic acid, MP 309° to 314°C (decomposes). The analytical sample from dimethylformamide melts at 314° to 316°C (decomposes). 

Nuvole et al. stated that the cyclization of 974 and its desmethyl derivative gave tautomeric 9-hydroxy-1,2,3-triazolo[4,5-/]quinoline-8-carboxyl-ates (e.g., 975) or 9-oxo-6,9-dihydro-l,2,3-triazolo[4,5-/]quinoline-8-car-boxylates (e.g., 976, depending on the cyclization conditions (in xylene on the action of polyphosphoric acid (PPA) vs. in DMF on the action of PPA and in Dowtherm A under boiling vs. in polyphosphate (89FES609, 89FES619). 

Ethyl 4,5-difluoro-7-oxo-2,3-dihydro-7//-pyrido[3,2,l-i)][2,l]benzox-azinone-6-carboxylate (98) was formed when ethyl 6,7-fluoro-4-hydroxy-8-(2-hydroxyethyl)quinoline-3-carboxylate (97) was treated with m-chloro-peroxybenzoic acid in chloroform [92JAP(K)92/208287, 92JAP(K)92/ 210656],... 

Dieckmann condensation of piperidine-2-carboxylate 138 in toluene in the presence of NaOEt furnished pyrido[l,2-h]pyridazine-3-carboxylate (139) (71CPB159). Ethyl 2-methyl-4-hydroxy-5,6-dihydro-4a//-pyridaz-ino[l,6-a]quinoline-3-carboxylate (7,8-benzolog of 139) was prepared similarly (66YZ613). 

The (lS)-5-amino-8,9-dihydroxy-2,3-dihydro-l//-pyrimido[l,2-a]quinoline-3-carboxylic acid (8) form of pyoverdin PaA was halogenated at position 7 with a 30-fold excess of ferric chloride and bromide in acidic water at room termperature for 18 h (97TL97). Acidic hydrolysis of (15)-5-amino-8,9-dihy droxy-2,3-hy dro-1 //-pyrimido [1,2-a] quinoline- 1-carboxylic acid (8) in boiling 6 N hydrochloric acid for 48 h gave the 5,8,9-trihydroxy derivative (90MI2). Treatment of 2,3-dihydro-l//-pyrimido[l,2-a]quinoline hydrochlorides with aqueous 10% sodium hydroxide gave 4a-hydroxy-2,3,4,4a-tetrahydro-l//-pyrimido[l,2-a]quinolines (60) (69YZ759). 

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