3- Oxobutyric acid

L-3-metliylvaline 3, 3-dimethyl-2-oxobutyric acid + Asp transaminase Cryptococcus leurentii 197... 

Chemical Name 3 chloro-4-cyclohexyl-a-oxo-ben2enebutanoic acid Common Name 4-(4 cvclohexvl-3-chlorophenyl)-4 oxobutyric acid Structural Formula ... 

Acylation of 270 with certain cyclic anhydrides 433 in acetic acid affords 4-oxobutyric acid derivatives 434. Cyclocondensation of these acids with acetic anhydride gives pyridazino[l,2- ]indazole-6,9,ll-triones 435 (Scheme 70) <2003MI1>. 

When male F-344 rats were injected with NNN-2 -14c, 75-95% of the dose was excreted in the 48 hr urine. In one experiment, the urine was collected in vessels containing DNP reagent. However, the DNPs of 4-hydroxy-l-(3-pyridyl)-l-butanone and 4-hy-droxy-4-C3-pyridy1)butanal were not detected. Since this was likely due to further oxidation in vivo, methods were developed for isolation of their probable oxidation products. This resulted in identification of the lactone, 5- C3-pyridyl)—tetrahydrofuran-2-one (1-2%), the keto acid, 4-(3-pyridyl).-4-oxobutyric acid (1-2%) and the hydroxy acid, 4-(3-pyridyl)-4-hydroxybutyric acid (26-40%) as urinary metabolites. These metabolites resulted. 

Ketoacid standard (3-methyl-2-oxobutyric acid, 2-ketoisovaleric) mix 50 mg in 25 ml (2 mg/ml) deionized water. Store the solution at 4°C. 

The isomeric l,2,4-triazin-5-ones also have herbicidal activity, and of these the 4-amino compounds stand out. Metribuzin (3) and metamitron (4) (68SAP6804409) possess excellent selectivity, the former being manufactured on a very large scale. Metribuzin can be synthesized from 3,3-dimethyl-2-oxobutyric acid (Scheme 3). 

Proprietary Names. Cinopal Lederfen. 4-(Biphenyl-4-yl)-4-oxobutyric acid C16H14O3 = 254.3 CAS—36330-85-5... 

Apart from sotolon, the other compounds in Fig. 5 can be explained as the products of a Maillard reaction, and their carbon skeletons simply originate from the active Amadori intermediate in other words, they still preserve the straight carbon chain structure of monosaccharides. In spite of being a simple Cg lactone, sotolon has a branched carbon skeleton, which implies another formation process in the Maillard reaction. Sulser e al.(6) reported that ethyl sotolon (ll) was prepared from threonine with sulfuric acid, and that 2-oxobutyric acid, a degradation product of threonine, was a better starting material to obtain II. This final reaction is a Claisen type of condensation, which would proceed more smoothly under alkaline conditions. As we(lO) obtained II from 2-oxobutyric acid (see figure 6) with a high yield in the presence of potassium carbonate in ethanol, a mixed condensation of 2-oxobutyric and 2-oxo-propanoic (pyruvic) acids was attempted under the same conditions, and a mixture of sotolon (22% yield) and II were obtained however, the... 

A direct way of obtaining (E/Z)-4- (pyrazolo[3,4-fr]pyridin-3-yl)hy-drazono pyrazol-3-ones 9a,b was reported by El-Dean et al. (91IJC(B)878) (Scheme 3) who heated (E/Z)-3-oxobutyric acid ethyl ester 8 with hydrazine hydrate 2a or phenylhydrazine 2b in glacial acetic acid. The products were isolated in 60% and 55% yield, respectively. 

Filippone and co-workers (05JOC4033) (Scheme 31) obtained hydra-zone 5b by heating 2-(dimethoxyphosphoryl)-3-oxobutyric acid ethyl ester 5a with semicarbazide in ethanol. Cyclization of 5b to pyrazol-3-one 133 required heating in tetrahydrofuran with sodium hydride which caused cleavage of the amide moiety at position 2 of the initially formed pyrazol-3-one. 

E.39) (E.39) Butanoic acid, 2-oxo-, 2-oxobutanoic acid, 2-oxobutyric acid, a-ketobutyric acid, methylpyruvic acid 600-18-0] FEMA 3733... 

Hofmann and Schieberle (1996) suggested hydroxyacetaldehyde and 2,3-butanedione as possible precursors of this odorant lactone. A mechanism of formation (in vin jaune ) has been proposed by Guichard et al. (1998) by transformation of threonine (present in coffee) into 2-oxobutyric acid (which can also be derived from carbohydrates), condensation with acetaldehyde and cyclization. 

A facile and efficient synthetic route to densely substituted thiophenes based on base induced cyclization reaction between thioamides derived from morpholine and a-haloketones has been reported. Thus, the thioamides 4 were subjected to treatment with the haloketones 5 (R = H, Ar, Me) under basic conditions to provide the tetrasubstituted thiophenes 6. Likewise, the reaction was also demonstrated to give good yields of thiophenes when the haloketones were replaced with 2-bromo-3-oxobutyric acid derivatives or propargyl bromide <04T6085>. 

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