ChemInform Abstract: UNTERSUCHUNGEN IN DER AZOLREIHE 91. MITT. REAKTIVITAET VON IMIDAZO(1,5‐A)PYRIMIDIN

Abstract

Das durch katalytische Hydrierung des entsprechenden Nitroderivats in neutraler wäßriger Lösung erhältliche Aminoimidazol (I) reagiert in situ in Gegenwart von Essigsäure mit Tetrarnethoxypropan (II) zu der Titelverbindung (III) (Ausbeute bezogen auf das Nitroimidazol) als Hauptprodukt; daneben entsteht das Isomere (IV).

4,4-Dialkoxybutan-2-ones as Synthons

“…The reaction of (R)-()-2-amino-2-phenylethanol (90) with (E)-methoxybutenone 3a gave (Z)-aminovinyl ketone 91 which was identified by 1 H NMR spectroscopy. Ketone 91 reacted with diethyl carbonate (92) to form oxazolidinone 93 which was reduced with sodium tetrahydridoborate to obtain a mixture of stereoisomeric alcohols 94 [73].…”

“…Acetal 4a was used in the synthesis of new unsaturated amino acids containing a pyrazolo[1,5-a]pyrimidine fragment [89]. Acetal 4a reacts with 2-aminoimidazole (127) to give 7-methylimidazo[1,5-a]pyrimidine (128) as the major product [17,90] In the condensation of acetal 4a with 4-amino-1,2,4-triazole (134), the contributions of pathways a and b are 58% and 20%, respectively, and the corresponding +2 A synthesis of pyrazolopyrimidines from methoxybutenone 3a was described in patents [100,101]; syntheses of these monomers and their homo-and heteropolymerizations were also developed. Biological additives to polymeric materials were synthesized on the basis of pyrazoles derived from diacetylene (1) [14].…”