5-Amino-4-oxo

Aus 3-Amino-4-hydrazinocarbonyl-pyrazol erhalt man nur mit Phenyl-trimethoxy-methan au-Ber 5-Amino-4-oxo-4,5-dihydro-yrazolo[3,4-d pyrimidin) 2- (3-Amino-4-pyrazol-yl)-5-phenyl-1,3,4-oxadiazol (45% Schmp. 233-2340)291. 

In continuation of our investigations on asymmetric nucleophilic acylations with lithiated a-aminonitriles [40], we envisaged the asymmetric synthesis of 3-substituted 5-amino-4-oxo esters A, bearing both a-amino ketone and 5-amino ester functionalities (Scheme 1.1.14) [41]. Since a-amino ketones are precursors of chiral p-amino alcohols [42, 43] and chiral amines [43], their asymmetric synthesis has the potential to provide valuable intermediates for the synthesis of biologically active compounds, including peptidomimetics [44]. The retrosynthetic analysis of A leads to the a-aminoacyl carbanion B and p-ester carbocation... 

Thus, the N,N-dibenzyl-protected aminonitrile 55 was prepared via Swern oxidation of N,N-dibenzylaminoethanol 54 followed by treatment with the enantio-pure amine auxiliary (S,S)-53 and HCN, resulting in the formation of a 3 2 epimeric mixture of the aminonitriles 55 in 55% yield, from which the single dia-stereomers could be isolated by chromatography. After lithiation with LDA, addition to the requisite (E)-a, P-unsaturated esters and hydrolysis of the aminonitrile moiety with silver nitrate, the desired a-amino keto esters R)-S6 were obtained with yields of 65-81% and enantiomeric excesses ee of 78-98%, which could be improved to ee > 98% by a simple recrystallization. Since the amino ketone functionality can be cleaved oxidatively, the 5-amino-4-oxo-esters 56 could be transformed to the corresponding succinic half-esters 57 with hydrogen peroxide in methanol in good to excellent yields (68-90%) (Scheme 1.1.15). 

Scheme 1.1.15 Enantioselective synthesis of 3-substituted 5-amino-4-oxo esters and succinic half-esters.

Chemical Name Pentanoic acid, 5-amino-4-oxo-, hydrochloride... 

Ethyl 5-amino-4-oxo-3-p-tolyl-3,4-dihydrothieno [3,4-d] pyridazin-l-carboxylate (295) and p-dimethylaminopropiophenone (presumably converted by loss of dimethylamine into phenyl vinyl ketone under the reaction conditions) probably gave the intermediate adduct (296) that lost H2S to afford ethyl 5-amino-7-benzoyl-4-oxo-3-p-tolyl-3,4-dihydro-1 -phthalazinecarboxylate (298) (Mc2NCHO, trace AcOH, reflux, 2h 61%) the same substrate (295) with p-methoxy-p-nitrostyrene likewise gave ethyl 5-amino-7-p-methoxyphenyl-6-nitro-4-oxo-3-p-tolyl-3,4-dihydro-l-phthalazinecarboxylate (297) (80%) and many analogs were made similarly. ... 

In contrast, the closely related substrate, ethyl 5-amino-4-oxo-3-phenyl-3,4-dihydrothieno[3,4-iflpyridazine-l-carboxylate (299), with acrylonitrile gave ethyl 5-amino-6-cyano -oxo-3-phenyl-8-thioxo-2,3,4,8-tetrahydro-l-phtha-... 

Just as a lactam can be opened to give an amino acid, an imide gives a similar reaction. A simple example is the hydrolysis of glutarimide, in this case prepared from furfural in four steps, to 5-amino-4-oxo-pentanoic acid (5-aminolevulinic acid, 2.81). This latter compound showed relatively high herbicidal activity. ... 

Pyrimido[4,5-6][l,4]diazepine, 6-aeetyl-2-amino-4-oxo-3,4,7,8,9-tetrahydro-biosynthesis, 3, 320 Pyrimido[4,5-c]furazan, 4-amino-reactions... 

Amino-4-oxo-5-phenylse)enazoiine, synthesis, amino-imino tautomerism, 262... 

CN (6/ -tra r)-7-[[(3,5-dichloro-4-oxo-l(4/f)-pyridinyl)acetyl]amino]-3-[[(5-methyl-l,3,4-thiadiazol-2-yl)thio]methyl]-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid... 

Novogrodosky, A., Nehring, RE., Jr and Meister, A. (1979). Inhibition of amine acid transport into lymphoid cells by the glutamine analog L-2-amino-4-oxo-5-chloropentanoate. Proc. Natl Acad. Sci. USA 76, 4932-4935. 

The reaction of potassium 3-amino-4-oxo-3,4-dihydroquinazoline-2-thiolate 62 with a-bromophenylacetic acid 63 resulted in the formation of (3-amino-4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl)-phenyl-acetic acid methyl ester 64 which on alkali treatment and subsequent acidification resulted in the synthesis of 2-phenyl- 1-thia-4,4a,9-triaza-anthracene-3,10-dione 65 <1999JCR(S)86>. Similarly, the reaction of potassium 3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- pyrimidine-2-thiolate 66 with a-bromo-ester 67 resulted in the formation of 2-(3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- / pyrimidin-2-ylsulfanyl)-propionic acid ethyl ester 68. Subsequent treatment with alkali followed by acidification resulted in the formation of 2,3,7-trimethyl-3a,9a-dihydro-l,8-dithia-4a,5,9-triazacyclopenta[ ]naphthalene-4,6-dione 69 <2000JHC1161>... 

As shown in Scheme 199, the 5-aminopyrimidine stmcture may be also incorporated into a more complex bicyclic system. Thus, diazotization of 3-amino-4-oxo-4//-pyrimido[ 1,23 lpyndazincs 1198 followed by treatment with 50% aqueous tetrafluoroboric acid results in precipitation of salts 1199. When heated with alcohols, nucleophilic attack on the carbonyl group opens the pyrimidine ring. The obtained species 1200 assume conformation 1201 that is more suitable for bond formation between the opposite charged nitrogen atoms. Alkyl l-(pyridazin-3-yl)-l//-l,2,3-triazole-4-carboxylates 1202 are obtained in 31-66% yield <2002ARK(viii)143>. 

Amino-2-oxo-4-pentenoic acid, see Pyridine Aminoparaoxon, see Parathion Aminoparathion, see Parathion jD-Aminoparathion, see Parathion Aminophenol, see Parathion... 

A similar degenerate ring transformation was observed when 4-amino-6-chloro-l-methylpyrazolo[3,4-(f]pyrimidine was treated with dilute alkali. In this reaction as well, the expected product, 4-amino-6,7-dihydro-6-oxo-l-methylpyrazolo[3,4-(f]pyrimidine, was not obtained, but rather a rearranged isomer, i.e., 6-amino-4,5-dihydro-4-oxo-l-methylpyrazolo-[3,4- f] pyrimidine. The formation of this compound takes place according to the same mechanism as that postulated for the formation of 86 (Scheme 11.39) (54JOC1570). 

Ring transformation involving the intramolecular reaction of a hydrazone or in situ formed hydrazone also appeared. The transformation of 6-methyl-2//-pyran-2,3,4-trione 3-arylhydrazones 332 into l-aryl-6-methyl-4-oxo-l,4-dihydropyridazine-3-carboxylic acids 333 is an example of the former (Scheme 82). Compound 332 are formed via reaction of 4-hydroxy-6-methyl-27/-pyran-2-one 331 with substituted benzenediazonium chlorides. These are normally not isolated and immediately used further <2005EJM1325>. An example where a hydrazone is formed in situ is the reaction of 2-amino-5-aryldiazenyl-4-oxo-6-phenyl-4//-pyran-3-carbonitriles 334 with H2SO4 in glacial acetic acid, yielding 2-aryl-6-benzoyl-3-hydroxy-5-oxo-2,5-dihydropyridazine -carbonitriles 335 (Scheme 83) <2001T6787>. 

Diamino-bcnzol reagiert in einer Redox-cyclisierung mit 2-Amino-4-oxo-4,5-dihydro-l,3-selenazol. Das Diamin kondensiert vermutlich liber ein spirocyclisches N,N-Acetal, das unter Selen-Abspaltung 2-Acetylamino-benzimidazol ( 100% Schmp. 312-315°) bildet317. 

Die Hydrolyse der 5-monosubstituicrten 4-Oxo-imidazolidine zu den freien a-Amino-car-bonsauren hangt vom 1 - Acyl- Rest ab 2 j 1 -Benzoyl-Verbindungen erfordern drastische... 

OCH, HsCt N COOCH, 0 0 H3C U CH3 (1.5) (2.0) F3C COOH analog Ver-fahren CH(CO-CH3)2 3-Acetyl-2-benzoyI-amino-4-oxo-pen tan-saure-methy tester 45 118-119 1... 

C synthons, synthetic equivalents of which being the amino-acetaldehyde-derived metallated aminonitrile D bearing the chiral auxiliary (S,S)-53 and an a,P-unsaturated ester E, respectively. This should make it possible to open up a pathway to an enantioselective conjugate addition of an a-aminoacyl carbanion equivalent D to enoates in order to access the target 3-substituted 5-ainino-4-oxo esters. 

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