Über einen neuen Zugang zu Imidazolen, sowie deren Verwendung zur Synthese von Purinen und 4,6‐Dihydro‐1,2‐dimethyl‐8‐phenylimidazo[4,5‐e]‐1,4‐diazepin‐5(1H)‐on

Abstract

Werrn Professor K. Mahlcr zum 90. Geburtstdg gewidmet (2O.VIII. 75) A novel route to imldaz,oles and their use for the syntheeis of purines and 4,6-dG hydro-l,?-dlmethyl-8-pheny~dazo[4,5-e]-l,4-d~zepln-~l~-on. Summary. Recently it has been shown [Z] that pyrimidines are avaihble from Thor+e-Ziegler cyclization of the appropriate dinitriles. As an extension of this work, a novel route to imidazoles has been developed.It has bean demonstrated that thcse imidawle derivatives are valuable intermediates for the synthesis of purines by application of standard procedures. Tho use of these imidazoles has enabled the preparation of some derivatives not accessible by other methods. Durch Thorpe-Z~~~~"Cyclisierung von Dinitden sind viele 5-,6und 7-gliedrige P-Cyan-efiamine und deren Folgeprodukte zughglich [l], In der vorausgegangenen Mitteilung [2] wurde gezeigt, dass der Aufbau des Pyrirnidinringes ausgehend von W-Cyano-N-(2-cyanoathy1)-acetarnidin rniiglich ist. In Fortfiihrung dieser Untersuchungen konnte erwartet werden, dass sich die bisher unbekannten N'-Cyano-Ncyanomethylderivate des Acetamidins zur Herstellung vdn Imidazolen eignen wiirden. Ein Hinweis dafiir bildete die leichte Cyclisierung von N-Cyanimino-dithiokohlensaureestern zu Imidazolen, uber die von Gomp$er et ad. [3] berichtet wurde.

Heterocycles from α‐Aminonitriles

“…[73] Like in the ester series, the electron-withdrawing effect of the nitrile function stabilizes neighboring diazo groups. [73] Like in the ester series, the electron-withdrawing effect of the nitrile function stabilizes neighboring diazo groups.…”

Synthesis of 4‐aroyl‐5‐nitro‐1H‐imidazoles and 4‐aroyl‐5‐aminoimidazoles

“…for C,H,,BrN,O,: C,35.3;H,4.0;N,13.7;Br,26.1. A sample was recrystallized (2x) from ethyl acetate-hexane to give off-white crystals, mp 237-240'; 'H nmr (deuteriochloroform): 6 2.48 (s,3,CH,),5, Ph). The filtrate was concentrated to give 10.85 g of solid which was recrystallized from dichloromethane-hexane to give 9.2 g (55%) of off-white crystals, mp 265-268O.…”

“…Recrystallization from methanol with the aid of activated carbon gave 2.7 g (38%) of white crystals, mp 239-241O; 'H nmr (deuteriochloroform): & 2.50 (5,3,CH,),(m,4,aromatic). The solution was stirred and heated on a steam bath while 12.0 g (0.024 mole) of 16 (Ar = 3-CF3Ph) was added in small portions.…”

“…Filtration gave 0.2 g (38%) of off-white crystals, mp 208-210'; 'H nmr (ds-DMSO): & 2.50 (5,3,CH,),4,aromatic), 13.1 (9-broad, NH). The residue was dissolved in dichloromethane, anhydrous hydrochloric acid added, followed by addition of ether.…”

Synthese von 5,6‐Dimethyl‐4‐oxo‐1,3,4,5‐tetrahydro‐imidazo‐[4,5‐c] [1,2,6]thiadiazin‐2,2‐dioxid und 7‐Methyl‐4‐oxo‐1H‐3,4‐dihydro‐pyrimido[4,5‐c][1,2,6]thiadiazin‐2,2‐dioxid

“…Die gegenwartige Mitteilung beschreibt die Herstellung des 2,2-Dioxids eines 2-Thia-analogen des Xanthins, namlich von 5,6-Dimethyl-4-oxo-l, 3,4,5-tetrahydro-imidazo [4,5-c] [ 1,2,6]thiadiazin-2,2-dioxid (4), ausgehend von dem leicht zuganglichen Imidazolderivat 3 [2] durch Ringschluss mit Sulfamoylchlorid [3].…”