Ethoxycarbonylamino acids

Ethoxycarbonylamino acids.1 (Ethoxycarbonyl)nitrene (2), generated by thermolysis of N(ethoxycarbonyl)-N,0-bis(trimethylsilyl)hydroxylamine (l),2 reacts with ketene silyl acetals to form N-protected a-amino esters (3) in 25-70% yield. 

Instead of the corresponding cyclized product, only the N-(, 2,4-thiadi-azol-3-yl)aminomethylenemalonate (1133) was obtained in 12% yield from the reaction of 3-amino-5-ethoxycarbonylamino-l,2,4-thiadiazole and EMME in polyphosphoric acid at 110°C for 3 hr (77JHC621). 

Bis(azidocarbonyl)pyrazine heated with anhydrous benzyl alcohol at 180° for 30 minutes, and then at 220° for 15 minutes gave 2,5-bis(benzyloxycarbonyl-amino)pyrazine (5), which with concentrated sulfuric acid foUowed by pouring onto ice afforded 2,5-diaminopyrazine (1176) but 2,5-bis(azidocarbonyl)pyrazine refluxed with ethanol gave 2,5-bis(ethoxycarbonylamino)pyrazine, which could not be converted into the amine with (fuming) hydrochloric acid to 210°, with concentrated sulfuric acid, or with potassium hydroxide (1172). 

Unsaturated polyester resins (UPER) are largely used as components in polymer composites 26, 27) Generally, they are obtained by reaction of an unsaturated polyester (UPE) with a vinyl monomer. In our experiments, we have cured the UPE represented in Figure 3 wifti styrene (STY), which is the monomer mostly used for this purpose, or hydroxyethyl acrylate (HEA) and/or a diblocked diisocyanate (i.e., acrylic acid 2-[6-(2-acryloyloxy-ethoxycarbonylamino)-hexylcarbamoyloxy]-ethyl ester, UA). The reaction is highly exothermic, thus allowing for a rapid FP. 

By heating 2-ethoxycarbonylamino-2-phenyl butyric acid 1170 with thionyl chloride, 4-ethyl-4-phenyl-oxazolidme-2,5-dione 1171 was formed [845]. 

C22H36N2O8 2-methyl-acrylic acid 2-((6-[l-methyl-2-(2-methyl-acryloyloxy)-ethoxycarbonylamino]-hexyl)-carbamoyloxy)-propyl ester 52723-94-1... 

The utility of bifunctional reagents such as oxalic acid monohydrazide for the resolution of racemic carbonyl compounds has been reported. Glyoxal reacts with ethyl carbamate under acid catalysis to give 1,1,2,2-tetra-(ethoxycarbonylamino)ethane (46) and not, as previously reported, glyoxal bis(ethoxycarbonylimide) (47). 

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