Showing papers by "University of Paderborn published in 1977"
TL;DR: In this paper, the Mannich reaction at 2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one was shown to lead to substitution at C-6.
Abstract: 2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-on (6a) reagiert mit Dimethylamin und Cyclo-pentylamin in Gegenwart von Formaldehyd zu den Mannich-Basen 6c und d. Aus 6c lies sich durch Druckhydrierung das Amin abspalten. Das Abbauprodukt war identisch mit 2-Amino-6-methyl-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-on (6b), das auf eindeutigem Syntheseweg erhalten worden war. Damit wird gezeigt, das die Mannich-Reaktion bei 6a im Gegensatz zu 3,7-Dihydropyrrolo[2,3-d]pyrimidin-4-on zur Substitution an C-6 fuhrt.
Mannich Reaction at 2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one, the Chromophore of the Ribonucleoside “Q”
2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one (6a) reacts with dimethylamine and cyclopentylamine in the presence of formaldehyde to form the Mannich bases 6c and d. From 6c the amine moiety was split off on hydrogenation under pressure. The degradation product was identical with 2-amino-6-methyl-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one (6b), which was obtained by unambiguous synthesis. This shows that in contrast to 3,7-dihydropyrrolo[2,3-d]-pyrimidin-4-one, Mannich reaction involving 6a leads to substitution at C-6.
33 citations
TL;DR: The phase transition of cholesteryl oleyl carbonate was indicated by the divergence of the wavelength of maximum light reflection as discussed by the authors, and the corresponding phase diagram shows two straight lines which intersect at 1.43 kbar and 52.0°C thus pointing to a change in transition order.
10 citations
TL;DR: The introduction of antigenic determining 2,4-dinitrophenyl residues into the rare ribonucleosides 4-thiouridine, and N3-(3-L-amino-3-carboxypropyl) uridine as well as into tRNA-Phe from E. coli has been investigated.
Abstract: The introduction of antigenic determining 2,4-dinitrophenyl residues into the rare ribonucleosides 4-thiouridine (1a), and N3-(3-L-amino-3-carboxypropyl) uridine (2) as well as into tRNA-Phe from E coli has been investigated Alkylation of 1a with omega-bromo-2,4-dinitroacetophenone (3b) gives S-(2,4-dinitrophenacyl)-4-thiouridine (5A) Applying the reaction to the 5'-monophosphate of 1a, 5b is formed, but this product decomposes at pH 7 However, acylation of 2 with 2,4-dinitrobenzoic acid N-hydroxysuccinimide ester (4b) leads to N3-[3-carboxy-3-L-(2,4-dinitrobenzamido)propyl]uridine (6) which is stable in aqueous solution The latter reaction was used for the introduction of an antigenic determining 2,4-dinitrophenyl residue into tRNA-Phe from E coli The modified tRNA-Phe was isolated and by degradation of the molecule with RNase T2 and alkaline phosphatase the nucleoside derivative 6 was obtained and found to be identical with the synthetic product
8 citations