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Synthesis of diazasteroids II . Synthesis of 8,11‐diaza‐2,3‐dimethoxygona‐1, 3,5 (10) , 9 (11) ‐tetraene
Author(s) -
Nagata Masanori,
Goi Masami,
Matoba Katsuhide,
Yamazaki Takao,
Castle Raymond N.
Publication year - 1973
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570100105
Subject(s) - chemistry , isoquinoline , nucleophile , sodium ethoxide , catalysis , medicinal chemistry , silica gel , ring (chemistry) , stereochemistry , organic chemistry , ethanol
Homoveratrylamine was condensed with 1‐cyanocyclopentene to afford the corresponding 2‐cyano‐ N ‐(3,4‐dimethoxyphenethyl)cyclopentylamine (III), which was ethoxycarbonylated with ethyl chlorocarbonate to give the trans ‐urethan (IVt) (major product) and the cis ‐urethan (IVc) which could be separated through a silica gel column. The cis ‐urethan was converted to the trans ‐urethan by the action of a catalytic amount of sodium ethoxide. Based upon general considerations of nucleophilic addition such as the Michael type reaction, the physical data obtained, and the difference in ease of cyclization of the 2‐aminomethyl‐ N ‐ethoxycarbonyl‐. N ‐homoveratrylcyclopentylamines (Vt and Vc) to the corresponding cyclic ureas (Vlt and VIc), it was concluded that the major product was the trans and the minor the cis isomer. The cyclized compounds, Vlt and VIc, were subsequently submitted to the Bischler‐Napieralski reaction furnishing the corresponding isoquinoline derivatives respectively. Thus the authors established a skeletal synthesis of the title compound, a 8,11‐diazasteroid, and its stereochemical configuration at the C/D ring juncture was elucidated.