Dicarbomethoxy acetylene

Dicarbadodecaborane, preparation and structure of, 5 342-343 Dicarbomethoxy acetylene, 45 48, 49 Dicarbon decaboranes, 26 85 base degradation, 26 90 bonding, 26 62 dianions, 26 78-79 reaction with Lewis bases, 26 85 1,2-Dicarbonic acid dichlorides, 33 300 Dicarbon nonaborane anion, oxidative coupling, 26 73... 

Divalent metal ions, reversible binding, 38 153 Dixenon cation, 46 68 Dizinc enzymes, 40 351-354 DMA, see Dicarbomethoxy acetylene DMAD complexes, see Dicarboxymethoxy dithiolene complexes DMAE, see Dimethylarsinoylethanol DMF, reduction potentials, 33 57 DMSO, see Dimethylsulfoxide DNA... 

Ethyl 3-anilinocrotonate (82) undergoes reaction with dimethyl acetylene-dicarboxylate (57) with the formation of two products, ethyl 5-anilino-3,4-dicarbomethoxy-trfl s,cM-2,4-hexadienoate (83) and ethyl 5-anilino-3,4-dicarbomethoxy-ci5, cw-2,4-hexadienoate (84). 

Krespan and McKusick have studied the addition reaction of dithietenes to various oleflnes and acetylenes. Thus, the reaction of 3,4-bis(trifluoromethyl)-l,2-dithiete (378) with DMAD gives a dithiin derivative (379), which loses sulfur on heating to give 2,5-dicarbomethoxy-4,5-bis(trifluoromethyl)thiophene (380) [Eq. (57)]. 

Acetylenic esters react with alkyl azides, aryl azides, carbo-alkoxy azides, and tosyl azide yielding triazoles in all cases studied.102-302-306 When dimethyl acetylenedicarboxylate (92) is the starting material, the 1-substituted 4,5-dicarbomethoxy-1,2,3-triazoles 93 are obtained. 

A-Methyl-/V-nitroso-a-(trimethylsilyl)benzylamine reacts thermally with DMAD to give 3,4-dicarbomethoxy-l-methyl-lH-pyrazole. The reaction is highly sensitive to the temperature upon increasing the temperature from 25 to 110 °C, the reaction time drops from 168 h to 3 min and yields increase from 30 to 100%. No reaction occurs from non-silylated /V-methyl-/V-nitrosobenzylamine. Other acetylenic esters have been successfully tested. In contrast, phenylacetylene gives a poor yield of the adduct and diphenylace-tylene does not react.473... 

N-Morpholino)-2,3-dicarbomethoxy-1,3-cycloheptadiene (3).3 Dimethyl acetylene dicarboxylate 1 (16.2 g, 77.4 mmol) was added to morpholinocyclopentene 2 (11 g, 77.4 mmol) in PhMe (40 ml.) under N2 with ice cooling and stirring at such a rate that the temperature never rose above 50°C. After a short supplementary stirring, the mixture was heated to reflux for 12 h. The solution was treated with excess of Et20 under cooling and the precipitate was filtered off. Recrystallization from Me2CO afforded 11.4 g of 3 (48%), mp 167-168°C. 

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