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Reaction of 2‐(5‐aminopyrazol‐1‐yl)quinoxaline 4‐oxides with dimethyl acetylenedicarboxylate
Author(s) -
Kurasawa Yoshihisa,
Katoh Ritsuko,
Mori Fumiko,
Fukuchi Minori,
Okamoto Megumi,
Takada Atsushi,
Kim Ho Sik,
Okamoto Yoshihisa
Publication year - 1992
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.5570290458
Subject(s) - dimethyl acetylenedicarboxylate , chemistry , quinoxaline , malononitrile , ethyl cyanoacetate , cycloaddition , medicinal chemistry , oxide , 1,3 dipolar cycloaddition , ring (chemistry) , organic chemistry , catalysis
The reaction of 6‐chloro‐2‐hydrazinoquinoxaline 4‐oxide 6 with ethyl 2‐(ethoxymethylene)‐2‐cyanoacetate or (1‐ethoxyethylidene)malononitrile gave 2‐(5‐amino‐4‐ethoxycarbonylpyrazol‐1‐yl)‐6‐chloroquinoxaline 4‐oxide 7a or 2‐(5‐amino‐4‐cyano‐3‐methylpyrazol‐1‐yl)‐6‐chloroquinoxaline 4‐oxide 7b , respectively. The reaction of compound 7a or 7b with dimethyl acetylenedicarboxylate resulted in the 1,3‐dipolar cycloaddition reaction and then ring transformation to afford 4‐(5‐amino‐4‐ethoxycarbonylpyrazol‐1‐yl)‐8‐chloro‐1,2,3‐trismethoxycarbonylpyrrolo[1,2‐α]quinoxaline 8a or 4‐(5‐amino‐4‐cyano‐3‐methylpyrazol‐1‐yl)‐8‐chloro‐1,2,3‐trismethoxycarbonylpyrrolo[1,2‐α]quinoxaline 8b , respectively.