METHOD FOR PRODUCTION OF CIS-1,2-DI(ALKYL SELENO) ETHENES Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: desired product has formula RSe-CH= CH-SeR where R is methyl, ethyl, isopropyl, tret-butyl. Cis-1,2-di-(methyl seleno) ethene having essential formula C₄H₈Se₂ is prepared by yield 83 its boiling point being 60-61 C/5 mm Hg. Cis-1,2-di-(ethyl seleno) ethene having essential formula C₆H₁₂Se₂ is prepared by yield 91 its boiling point being 80-82 C/5 mm Hg. Cis-1,2-di-(isopropyl seleno) ethene having essential formula C₈H₁₆Se₂ is prepared by yield 80 its boiling point being 92-95 C/5 mm Hg. Cis-1,2-di-(tret-butyl seleno) ethene having essential formula C₁₀H₂₀Se₂ is prepared by yield 86 its boiling point being 85-87 C/1 mm Hg. Dialkyl diselenide is used as reagent 1, acetylene is used as reagent 2. Reaction is carried out in the medium of organic solvent (e.g. benzene, toluene) in the presence of potassium hydroxide and interphase catalyst, molar ratio diselenide:KOH:catalyst being 1:(1-18):(0.03-0.07). The process takes place at 20-90 C, pressure of atmosphere and acetylene pressure being 12-14 atm. Dibenzo-18-craun-6 is used as mentioned above interphase catalyst. EFFECT: improves efficiency of the method.