Cc. Leznoff et Dm. Drew, THE USE OF BISPHTHALONITRILES IN THE SYNTHESIS OF SIDE-STRAPPED 1,11,15,25-TETRASUBSTITUTED PHTHALOCYANINES, Canadian journal of chemistry, 74(3), 1996, pp. 307-318
Nucleophilic aromatic substitution reactions of 3-nitrophthalonitrile
yield 3-hydroxyphthalonitrile and 3-neopentoxyphthalonitrile, the latt
er of which condensed to 1,8,15,22-tetraneopentoxyphthalocyanine as a
mixture of isomers. Bisphthalonitriles such as 1,3-bis(2',3'-dicyanoph
enoxy)-2,2-dipentylpropane, 1,3-bis(2',3'-dicyanophenoxy)-2,2-diethylp
ropane, 1,3-bis(2',3'-dicyanophenoxy)-2,2-dioctylpropane, and -dicyano
phenoxy)-2-methyl-2-trityloxymethylpropane all gave bis-crown-like 1,1
1,15,25-tetrasubstituted phthalocyanines as pure compounds when treate
d with lithium octoxide in 1-octanol at 196 degrees C. A host of nine
other bisphthalonitriles including 1,5-bis(2',3'-dicyanophenoxy)-3-oxa
pentane, 1,1 -bis(2',3'-dicyanophenoxymethyl)cyclohexane, 1,2-bis(2',3
'-dicyanophenoxymethyl)benzene, and 2,5-bis(2',3'-dicyanophenoxymethyl
)furan did not dimerize to mononuclear phthalocynaines. The ''gem dime
thyl'' effect was suggested as a reason for the successful macrocycliz
ations.