1-Alkyl-1,2,3,4-tetrahydroquinoxalines¹

Abstract

The intense, wartime search for new chemical series which might show antimalarial activity has

Synthesen von Chinoxalin‐Derivaten

“…1-Benzolsulfo-bzw. 1-Toluolsulfo-Derivate waren aber, wie bereits bekannt [5], ohne Schwierigkeiten darstellbar. Die Umsetzung der Tetrahydrochinoxaline rnit Butylisocyanat fuhrt zu schon kristallisierten 1,4-Bis-butylcarbamaten (LXX, LXXIV).…”

“…3-methylierte Chinoxalone wurden am N-1 mit Hilfe von Natriumathylat (XLI, XLV, XLVIII, XLIX, LII, Tab. 3 ) bzw 5). Durch Quartarisierung wurden schon kristallisierte Substanzen rnit charakteristischen Schmelzpunktcn erhalten.…”

Lithiumgewinnung aus anspruchsvollen Lagerstätten: Zinnwaldit und magnesiumreiche Salzseen

“…Solvent was removed in roto‐evaporator and the dark brown sticky solid obtained was passed over silica gel column to remove base impurities (Eluent: 70% ethyl acetate in hexane). 6‐Methoxyquinoxaline was obtained as white solid in excellent yield, 13.6 g (85%), mp 58–60°C (Lit mp 60°C [18]).…”

Synthesis and Crystal Structure of Novel N-Acyl-N′-Dichloroacetyl-6,7-Dichloro-1,2,3,4-Tetrahydroquinoxalines Derivatives

“…Cavagnol developed a route for the preparation 1-alkyl derivatives by low temperature acylation with benzenesulfonyl chloride to give the phenylsulfonyl-1,2,3,4tetrahydro-1-quinoxaline, alkylating the monophenylsulfonyl derivative to l-alkyl-4-phenylsulfonyl-l,2,3,4-tetrahydroquinoxaline followed by hydrolysis which yielded 1-alkyl-1,2,3,4-tetrahydroquinoxaline. 14 Later mono and di-substituted alkyl and aryl quinoxalines were rapidly reduced in high yield to their respective 1,2,3,4-tetrahydro-derivatives by borane in THF solution. 15 However, all these methods proceeded with moderate to good yields but required substantial purification procedures and extended reaction times.…”