Wentrup, Curt published the artcile3-pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides and ring contraction to cyanopyrroles and cyanoindoles, Synthetic Route of 26187-28-0, the publication is Beilstein Journal of Organic Chemistry (2013), 743-753, database is CAplus and MEDLINE.
Precursors of 3-pyridylnitrene and 2- and 4-pyrimidinylcarbenes all afford mixtures of 2- and 3-cyanopyrroles on flash vacuum thermolysis, but 3-cyanopyrroles are the first-formed products. 3-Quinolylnitrenes and 4-quinazolinylcarbenes similarly afford 3-cyanoindoles. 2-Pyrimidinylcarbenes rearrange to 3-pyridylnitrenes, but 4-pyrimidinylcarbenes and 4-quinazolinylcarbenes do not necessarily rearrange to the corresponding 3-pyridylnitrenes or 3-quinolylnitrenes. The ring contraction reactions are interpreted in terms of ring opening of either the nitrenes or the diazacycloheptatetraenes to nitrile ylides.
Beilstein Journal of Organic Chemistry published new progress about 26187-28-0. 26187-28-0 belongs to nitriles-buliding-blocks, auxiliary class Pyrrole,Nitrile, name is 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, and the molecular formula is C2H2N4O2, Synthetic Route of 26187-28-0.
Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts