US EPA

3761731 

Journal Article 

Unusual stabilization of 1,2-diamino derivatives of quincorine and quincoridine by carbon dioxide: Persistent crystalline prim-ammonium-carbamate salts and their reactivity towards isatoic acid anhydride 

Neda, I; Kaukorat, T; Fischer, AK 

2003 

Yes 

European Journal of Organic Chemistry
ISSN: 1434-193X
EISSN: 1099-0690 

Wiley-VCH Verlag 

19 

3784-3790 

English 

10.1002/ejoc.200300211 

WOS:000185734000011 

http://doi.wiley.com/10.1002/ejoc.200300211
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The reaction of N-methylisatoic anhydride 1 with a series of quincorine (QCI) and quincoridine (QCD) derivatives furnished the corresponding QCI- and QCD-substituted anthranilic acid amides 4-9. In the synthesis of 4-9, we investigated the influence of the C5 substituent of 2-aminomethyl derivatives of QCI and QCD on their basicity and polarity and, therefore, on their reactivity towards isatoic acid anhydride. By exposing a number of 2-aminomethyl derivatives of QCI and QCD to (carbon dioxide from) air, the formation of carbon dioxide adducts 10-15 was observed. In an unusual reaction, we obtained the first set of chiral ammonium carbamates derived from primary amines, which provides a convenient method for purifying and stabilizing aminomethyl derivatives of QCI and QCD. All compounds were fully characterized by spectroscopic methods. In addition, the structure of 11 was proved by X-ray crystal structure determination. The heterocyclic nitrogen atoms display trigonal-pyramidal coordination geometries; the amido group is essentially planar. N-2′ of the ammonium ion is a triple hydrogen bond donor to the carboxylato oxygen atoms of three different carbamate anions. The resulting net effect is a hydrophilic plane parallel to the ab plane. The crystal packing involves six classical hydrogen bonds. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003. 

amino alcohols; carboxylation; nitrogen heterocycles