Rf. Fandy et al., Synthesis of arylnaphthoquinones and their reactions with o-substituted primary aromatic amines, I J HET CHE, 10(3), 2001, pp. 209-214
Cycloaddition reaction of 2-aryl-1,4-benzoquinones 1a-d with a number of di
fferent dienes namely 2,3-dimethylbutadiene; 1,4-diphenylbutadiene and anth
racene yield 2-aryl-6,7-dimethyl-1,4-naphthoquinones 3a,b; 2,5,8-triphenyl-
1,4-naphthoquinone 4 and 2-aryl-1,4,9,10-tetrahydro-9,10-o-benzoanthracene-
1,4-dione 5 respectively. in addition, the cycloaddition reaction of 2-aryl
-1,4-benzoquinones 1d,e with 2,3-dimethylbutadiene was also investigated to
yield 2-aryl-5,8-dihydro-6,7-dimethyl-1,4-naphthohydroquinones 2a,b. Cyclo
condensation reactions of Diels-Alder adducts 2b, 3b, 5a with ethylenediami
ne; o-substituted primary aromatic amines gave, quinoxaline, phenazine, phe
noxazine and phenothiazine heterocyclic derivatives (6-14).