Furan 3-acetamido-5-

Chromogens I and III were found to contain, respectively, one and two double bonds the hydrogenated derivatives gave no reaction with the Ehrlich reagent. Chromogen III was formulated as 3-acetamido-5-(l,2-dihydroxyethyl)furan (CXIX), and was found to be identical with the syn-... 

Both 2- and 3-nitrothiophenes are reduced by tin and hydrochloric acid to the corresponding aminothiophenes. Reduction of 2,5-dibromo-3,4-dinitrothiophene gives 3,4-diaminothiophene as a stable crystalline solid. 2-Acetamido-furans are prepared by the reduction of 2-nitrofurans in the presence of acetic anhydride. 2-Substituted 5-nitrofurans can be reduced to the S-aminofurans by an electrochemical method. Although catalytic reduction gives 2-aminofurans only in low yields, they can be trapped using ethyl ethoxymethylenecyanoacetate or ethoxymethylenemalononitrile. Benzofuranone 412 and not 2-aminobenzofuran is obtained from tin and hydrochloric acid treatment of 2-nitrobenzo[ ] furan 411. 

The traditional method of assay of 2-acetamido sugars is the Morgan-Elson reaction. This involves treatment of the sugars in base, which produces furans, and reaction of these furans in situ with Ehrlich s reagent (p-dimethylamino-benzaldehyde in acid), which generates delocalised chromophores, as shown in Figure 7.8." ... 

Similar /3-eliminations occur with 2-acylamino-2-deoxyaldoses, and an enamine derivative believed to be 2-acetamido-2,3-dideoxy-D-erj/after treatment of 2-acetamido-tetra-O-acetyl-2-deoxy-/3-D-glucose under basic conditions (91) was also thought to be the first product formed in the Morgan-Elson test for 2-acetamido-2-deoxyhexoses. < >> Although furan compounds are ultimately formed in this reaction, there would seem to be small reason to doubt that a single elimination from a simple derivative of n-glucose would give an unsaturated, pyranoid product. 

A mixture of ethyl -acetamido-a-cyanopropionate, LiBH4, and dry tetrahydro-furan refluxed 2 hrs., dil. with methanol, acidified with HCl, evaporated to dryness, twice more dissolved in methanol, heated to boiling and evaporated to remove boric acid as methyl borate, the residue refluxed 8 hrs. with 6 N HCl a-methylserine. Y 84%. F. e. s. J. M. Stewart, J. Org. Chem. 26, 3360 (1961). 

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