Acetylenic derivatives of heterocycles. 8. New route to the synthesis of ethynylpyrazoles was written by Vasilevskii, S. F.;Shvartsberg, M. S.;Kotlyarevskii, I. L.. And the article was included in Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya in 1971.Name: 5-Iodo-1-methyl-1H-pyrazole This article mentions the following:
The catalyzed substitution of halogen by an acetylenic group in heterocyclic compounds was applicable to pyrazoles. BuLi and 1-methylpyrazole mixed in the cold and held 1 hr at room temperature, treated with iodine at 5° and made alk. with aqueous NaOH, gave 5-iodo-1-methylpyrazole, which in AcOH-CCl4 with iodine-HIO3 in the presence of 30% H2SO4 gave in 15 min at 75° the 4,5-diiodo analog. 3,4-Diiodopyrazole and Me2SO4 in dioxane-40% NaOH gave 1-methyl-4,5-diiodopyrazole and the 3,4-diiodo analog in nearly equal yields. Similar methylation was used to prepare 3,4,5-triiodo-1-methylpyrazole. The iodopyrazoles and HCCCMe2OCHMeOEt heated at 111-14° with activated powd. Cu and K2CO3 in pyridine gave the appropriately substituted acetylenic derivatives from stoichiometric proportions of reactants used. These acetals were hydrolyzed with 1:3 aqueous HCl 2-3 hr to the acetylenic alcs. which heated with powd. KOH afforded pyrazolylacetylenes in 41-73% yields. In the experiment, the researchers used many compounds, for example, 5-Iodo-1-methyl-1H-pyrazole (cas: 34091-51-5Name: 5-Iodo-1-methyl-1H-pyrazole).
5-Iodo-1-methyl-1H-pyrazole (cas: 34091-51-5) belongs to iodide derivatives. Organic iodides can be alkyl, alkenyl, or alkynyl, and all of them are very reactive toward with many kinds of nucleophiles. Polyiodoorganic compounds are sometimes employed as X-ray contrast agents, in fluoroscopy, a type of medical imaging. This application exploits the X-ray absorbing ability of the heavy iodine nucleus.Name: 5-Iodo-1-methyl-1H-pyrazole
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com