Synthesis of pyrazolo[1,5-c]quinazoline derivatives through the copper-catalyzed domino reaction of o-alkenyl aromatic isocyanides with diazo compounds was written by Liu, Lu;Li, Lei;Mao, Shukuan;Wang, Xin;Zhou, Ming-Dong;Zhao, Yu-long;Wang, He. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2020.SDS of cas: 76437-44-0 This article mentions the following:
A novel copper-catalyzed domino reaction between o-alkenyl aromatic isocyanides and diazo compounds was developed under mild reaction conditions. Various o-alkenyl aromatic isocyanides were prepared from readily available reactants. The reaction provided a general and efficient method for synthesis of pyrazolo[1,5-c]quinazolines I [R1 = cyclohexyl, 2-thienyl, 2-naphthyl, etc.; R2 = H, 8-MeO, 7-Cl, etc.; R3 = OEt, OBn, 4-ClC6H4, etc.] by the formation of two rings and three new bonds in a single step from readily available acyclic starting materials. A mechanism involving a tandem (3+2) cyclization/elimination/intramol. aza-addition sequence was proposed. In the experiment, the researchers used many compounds, for example, 1-(Bromomethyl)-4-fluoro-2-nitrobenzene (cas: 76437-44-0SDS of cas: 76437-44-0).
1-(Bromomethyl)-4-fluoro-2-nitrobenzene (cas: 76437-44-0) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. The reactivity of organobromine compounds resembles but is intermediate between the reactivity of organochlorine and organoiodine compounds. For many applications, organobromides represent a compromise of reactivity and cost.SDS of cas: 76437-44-0
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary