A novel synthetic methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylene from CaC and water. Partitioning of the reactants improves the yields of desired pyrazoles up to 99% and simplifies their isolation to a simple procedure of solvent evaporation. The approach requires no complex equipment and utilizes inexpensive, safe, and easy to handle calcium carbide as a starting material. A model deuterium incorporation is carried out according to the developed methodology, producing a series of novel 4,5-dideuteropyrazoles with excellent deuterium enrichment. Theoretical calculations on reaction mechanism and characterization of possible intermediate structures were performed.

Recent progress in the leading synthetic applications of acetylene is discussed from the prospect of rapid development and novel opportunities. A diversity of reactions involving the acetylene molecule to carry out vinylation processes, cross-coupling reactions, synthesis of substituted alkynes, preparation of heterocycles and the construction of a number of functionalized molecules with different levels of molecular complexity were recently studied. Of particular importance is the utilization of acetylene in the synthesis of pharmaceutical substances and drugs. The increasing interest in acetylene and its involvement in organic transformations highlights a fascinating renaissance of this simplest alkyne molecule.

In this work, a novel synthetic methodology for the one-pot preparation of isoxazoles directly from the reaction of calcium carbide with aldoximes is reported.

Synthetic methodology enabled by 13C-elemental carbon is reported. Calcium carbide Ca13C2 was applied to introduce a universal 13C2 unit in the synthesis of labeled alkynes, O,S,N-vinyl derivatives, labeled polymers and 13C2-pyridazine drug core.

A novel methodology for the preparation of trideuterovinyl derivatives of high purity directly from alcohols, thiols, and NH-compounds was developed. Commercially available calcium carbide and D2O acted as a D2-acetylene source, and DMSO-d 6 was used to complete the formation of the D2C=C(D)–X fragment (X = O, S, N). Polymerization of a selected trideuterovinylated compound showed a very promising potential of these substances in the synthesis of labeled polymeric materials. Biological activity of the synthesized trideuterovinyl derivatives was evaluated and the results indicated a significant increase of cytotoxicity upon deuteration.