2-Amino-4,5-dihydroxy-4,5-dihydro

ZN(C)153, 00ZN(C)323, 00ZN(C)857, 01MI2, 01MIP4, 01TL5849). 5-Amino-8,9-dihydroxy-2,3-dihydro-l//-pyrimido[l,2-u]quinoline-3-carboxylic acid moiety 4 was also identified as a chromophoric moiety of certain... 

Ar-quinolin-2-yl)imino]propionates by injection or sublimation at 530°C yielded a mixture of 3-amino- and 3-ethoxy-l//-pyrimido[l,2-rz]quinolin-l-ones <2004AJC577>. An oxidative cascade for the biomimetic formation of the pyoverdine chromophore was supported by incubation of 2-[(4-hydroxyphenyl)- and 2-[(2-(3,4-dihydroxipheny-l)ethyl]-l,4,5,6-tetrahydropyrimidines with polyphenol oxidase or Pseudomonas extract to afford a mixture of 8,9-dihydroxy-2,3-dihydro- and -2,3,5,6-tctrahydro-l //-pyrimido[ 1,2- ]quinolines <20030L2215>. Oxidation of 2-[(2-(3,4-dihydroxiphenyl)ethyl]-l,4,5,6-tetrahydropyrimidine with MnOz gave a similar result. 

Chorazepate Chorazepate, 7-chloro-2,3-dihydro-2,2-dihydroxy-5-phenyl-1H-1,4-benzo-diazepin-3-carboxylic acid (5.1.34), which is used in the form of a dipotassium salt, is synthesized by yet another interesting synthetic scheme. 2-Amino-5-chlorobenzonitrile is used as the initial compound, which upon reaction with phenyhnagnesiumbromide is transformed into 2-amino-5-chlorbenzophenone imine (5.1.32). Reacting this with amino-malonic ester gives a heterocyclization product, 7-chloro-l,3-dihydro-3-carbethoxy-5-phenyl-2H-benzodiazepin-2-one (5.1.33), which upon hydrolysis using an alcoholic solution of potassium hydroxide forms a dipotassium salt (5.1.34), chlorazepate [30-32]. 

Aus a-Dicarbonyl-Verbindungen und Amidinen bilden sich zunachst 4,5-Dihydroxy-4,5-dihydro-imidazole, die isoliert werden konnen127 128. Setzt man eine disubstituierte a-Dicarbonyl-Verbindung und statt des Amidins ein Guanidin-Derivat ein, so erhalt man unter Abspaltung eines Aquivalents Wasser 4,5-disubstituierte 2-Amino-4-hydroxy-4H-imidazole, die in vielen Fallen ebenfalls isoliert werden konnen129,130 ... 

Applications of the Conrad-Limpach reaction to the synthesis of 1-hydroxy-4,7-phenanthrolines or, more correctly, l-oxo-l,4-dihydro-4,7-phenanthrolines, from p-phenylenediamine or 6-aminoquinolines continue to be reported. l,10-Dihydroxy-3,8-dimethyl-4,7-phenanthroline has again been prepared from p-phenylenediamine,234 hot diphenyl ether being used to effect the cyclization. Other examples include the new or improved preparations of l-hydroxy-3-methyl-, 10-amino-l-hydroxy-3-methyl-,232 2-(y-chlorocrotonyl)- l,10-dihydroxy-3,8-dimethyl-, and 2,9-bis (y- chlorocrotonyl)-1,10- dihydroxy - 3,8 - dimethyl - 4,7 - phenanthro-lines.235 Compounds prepared in this way have been patented as antiasthmatic agents.178 A closely related synthesis employing poly-phosphoric acid as cyclizing agent has yielded l-hydroxy-3-phenyl-4,7-phenanthroline.236... 

Acidic hydrolytic products of pyoverdins, (lS)-5-amino-8,9-dihydroxy-(8) and 5,8,9-trihydroxy-2,3-dihydro-l//-pyrimido[l, 2-a]quinolines-3-carboxylic acids were characterized by 13C NMR investigations in DMSO-d6, DMF-d7, and in 1 N DC1 solutions [91ZN(C)993],... 

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). 

The described synthesis of l,4-thiazino[3,2-6][l,4]thiazine (305) <87JA4308> starts with the reaction of aqueous glyoxal (302) with iV-methylguanidinium chloride (303) in water (pH 8). The resulting 2-amino-4,5-dihydro-4,5-dihydroxy-l-methylimidazolium chloride (304) is treated with 2-amino-ethane thiol in H20 (pH 8-9) to give either (305) or (306). The NMR spectrum of the product supports both of the structures (305) and (306) there is only one diastereomer <87JA4308>. 

Amino-4-hydroxy-8-methyl- E19d, 689 (aus 1,3-Oxazol-Der.) 7-Aminoxy-4-methyl- El 6a, 264 Furan 3,4-Dihydroxy-5-imino-2-phenyl-2,5-dihydro- VI/2, 698 Glyoxylsaure (3,4-Dimethoxy-phenyl)- -nitril E13/2, 1158 (Alkohol - Keton)... 

Dioxo-3-ethyl-l, 5,6,7-tetrahydro- 677 Pyrazolo[3,4-d]-l, 3-oxazin l,3-Dimethyl-4-oxo-6-(2-oxo-propyl)-dihydro- 557 1- Acyl-3-methylthio-6-oxo-l,6-dihydro- 676 2- Benzyl-6-(4-nitro-phenyl)-4-oxo-2,4-dihydro-676 4-Amino-7-chlor-phenyl- 976 2-(4-Aminosulfonyl-phenyl)-4,7-dichIor- 977 2-(4-Aminosulfonyl-phcnyl)-4,7-dihydroxy- 922 4-Anilino-7-chlor-2-(3-thienyl)- aus 4,7-DichIor-2-(3-thicnyI)- pyriclazino-[4,5-d]-l,3-thia7.ol)/Ethanol 976 7-Chlor-4-ethoxy-2-methyl- 972 7-Chlor-4-methoxy-2-phenyl- 972 7-ChIor-4-(3-pyrroIidino-propyloxy)-2-(2-thienyI)- 972... 

N 3 6-Amino-1-methy]-5-phenyl- 688 6-Amino-5-phenyl- 688 5.6-Dihydroxy- 7-Amino-2,5-bis-[methylthio]-3-cyan- 693 7-Amino-3-cyan-5-methylthio-7-morpholino- 693 4-Aryloxy-2,2-dimethyI-4,5-dihydrO- 693 2-Aryl-4-pheny]-l,2,3,4-tetrahydro- 693 5,5-Dimethyl-7-(4-methyl-phenyloxy)-4,5-dihydro-... 

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