Methylglyoxal

HC CH(0H) CH20H. optically active. D-glyceraldehyde is a colourless syrup. May be prepared by mild oxidation of glycerol or by hydrolysis of glyceraldehyde acetal (prepared by oxidation of acrolein acetol). DL-glyceraldehyde forms colourless dimers, m.p. IBS-S C. Converted to methylglyoxal by warm dilute sulphuric acid. The enantiomers... 

For the synthesis of 4-nitropyridazines a new approach has been developed in which the hydrazide of nitrothiolacetic acid or the corresponding amidrazone (162) reacts with glyoxal or methylglyoxal (Scheme 86) (77TL3619). 

Methylglyoxal [78-98-8] M 72.1, b ca 72 /760mm. Commercial 30% (w/v) aqueous soln was diluted to about 10% and distd twice, taking the fraction boiling below 50 /20mm Hg. (This treatment does not remove lactic acid). 

As the reaction sequence of Scheme 12-38 can be stopped at the stage of the oo-methylglyoxal phenylhydrazone (12.78), it is possible to synthesize asymmetrically substituted formazanes (12.80, Ar = Ar ) by reacting acetone with one equivalent of a diazonium ion ArNJ under acidic conditions and then coupling the co-methyl-glyoxal phenylhydrazone with Ar NJ in alkaline solution. 

C3H7NO2 107-97-1) see Flumazenil methylglyoxal diethyl acetal (C7H14O2 5774-26-5) see Betacarotene... 

Liyanage H, S Kashket, M Young, ER Kashket (2001) Clostridium beijerinckii and Clostridium difficile detoxify methylglyoxal by a novel mechanism involving glycerol dehydrogenase. Appl Environ Microbiol 67 2004-2010. 

Clostridium bifermentans reduced 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene, and a metabolite was formed by reaction of one of the amino groups with methylglyoxal (Lewis et al. 1996). 

A cross-coupling reaction of aldehydes with a-diketones proceeded in the presence of water to give the corresponding adducts in moderate to good yield. It is possible to use the substrates such as phenyl-glyoxal monohydrate, aqueous methylglyoxal, formalin, and aqueous a-chloroacetaldehyde for this reaction.330... 

Murata, K., Fukuda, Y., Shimosaka, M., Watanabe, K., Saikusa, T., and Kimura, A., Phenotype character of the methylglyoxal resistance gene in Saccharomyces cerevisiae Expression in Escherichia coli and application to breeding wild-type yeast strains, Appl Environ Microbiol, 50 (5), 1200-1207,1985. 

Reaction of 6-aminopyrimidines with 2 mol of a-ketoaldehyde in aqueous medium gave rise to the zwitterionic a-iminocarboxylic acids thus, 214 with methylglyoxal gave the pyrimido[l,6- ]pyrimidin-2-carboxylic acid 215 (Equation 26) <2005W02005/039589>. 

Water-soluble methylglyoxal adenine derivative 11 has recently been reported as a potentiator of wild-type and F508del-CFTR mutations in several cell lines [55]. Ex vivo addition of 11 to cftr mice colonic epithelium induced a dose-dependent elevation of chloride secretion with a measured EC50 of 175 + 1.1 pM. In vivo, in cftr+/ mice, addition of 11 in the presence of isoprenaline induced a dose-dependent salivary secretion with an EC50 of 7.1 + 1.1 pM whereas no effect of isoprenaline and 11 was observed on the salivary secretion of cftr mice. 

The extent of oxidation, when determined by the reaction of the product with phenylhydrazine, is 85%. Hydrolysis of the oxidized xylan should produce approximately equimolar quantities of D-glyceraldehyde and glyoxal. Experimental determination of glyceraldehyde indicates 67 % of the theoretical when the oxidized xylan is distilled with sulfuric acid and the evolved methylglyoxal measured as the phenylosazone. Glyoxal is isolated in 63% yield, when separated as the phenylosazone or as the dioxime. Aldehyde groups in the oxidized xylan may be further... 

The reverse process, conversion of >CH2 into >CO succeeds in the case of ketones with selenium dioxide. Thus acetone may be directly oxidised to methylglyoxal. This oxidising agent has been used very frequently recently because of the great variety of ways in which it can be applied. 

Propanediol. In its racemic form, 1,2-propanediol is a petroleum-based high-volume chemical with an aimual production of over 500,0001, mostly used to manufacture the unsaturated polyester resins, yet also featuring excellent antifreeze properties. Enantiomerically pure (/ )-1,2-propanediol accumulates along two different pathways via DAHP (3-deoxy-D-flrahmo-heptulosonic acid 7-phosphate) and methylglyoxal, which then is reduced with either... 

---