Acetylenedicarboxylic acid

Acetylenedicarboxylic acid ester reacts with (184) in benzene-pentene at 20 °C to give the 3 1 adduct (185) (77AG(E)177). 

Acetylenedicarboxylic acid monopotassium salt [928-04-1] M 152.2. Very soluble in H2O, but can be crystd from small volume of H2O in small crystals. These are washed with EtOH and dried over H2SO4 at 125°. [Chem Ber 10 841 1877, Justus Liebigs Ann Chem 272 133 1893.]... 

Both acetylenedicarboxylic acid and its ester undergo Michael addition reactions with a variety of nucleophilic reagents. An example is... 

Pyrroles react at free a- or -positions with acetylenedicarboxylic acid or the methyl ester yielding mixtures of the corresponding maleic and fumaric acid derivatives. Protons are readily available to satisfy... 

Acetylenedicarboxylic acid is known to combine with a number of pyrroles but only in the case of 1-benzylpyrrole have the products been rigorously examined. Mandell and Blanchard showed that in this case a mixture of the maleic anhydride (35), the fumaric acid (36), and the Diels-Alder type adduct (38) was formed. 

Diels et al. showed that acetylenedicarboxylic acid and 1-methyl-pyrrole gave l-methyl-2-pyrrylmaleic anhydride (41) and a second compound. The anhydride on hydrogenation and conversion to the corresponding dimethyl ester gave the same product as obtained from 1-methylpyrrole and maleic anhydride, followed by hydrolysis and... 

Methylindole and acetylenedicarboxylic acid is reported to give two unidentified products, but with the dimethyl ester the crs and trans (61) adducts were obtained. It was suggested that the major product had the trans configuration but this was not proved. Hydrogenation of both adducts gave the corresponding succinic ester, which was also obtained from 2-methylindole and maleic anhydride, followed by esterification. 

Irradiation of 5-acetyldibenz[i>,/]azepine (19) in the presence of. V-methylmaleimide results in a mixture of the homo dimer 20 and the mixed dimer 21. No [2 + 2] cycloadducts are obtained, however, with other alkenes such as styrene, acetylenedicarboxylic acid, dimethyl fumarate or acrylonitrile.32 Later studies have demonstrated that the dimerization occurs via the excited triplet state.196... 

The rate of permanganate oxidation of acetylenedicarboxylic acid to CO2 at pH 0.25-5.0 requires the use of the stopped-flow method, which yielded simple... 

Krapcho and Vivelo have described a new formal total synthesis of tropinone (124) and ( )-cocaine (98) (94). Cycloaddition of IV-methylpyrrole (182) and acetylenedicarboxylic acid leads to 183, which is hydrogenated to 184. The diacid mixture 184 is refluxed in MeOH/HCl to yield the diester mixture 185. Addition of this to an excess of metallic sodium in liquid ammonia at — 78°C leads to the N-methylpyrrolidine derivative 186 (cf. 95), whose diethyl analog 147 has earlier been converted to tropinone (124) and (+)-cocaine (98) (78-80) (Scheme 13). 

Isopropanol forms 2 1 adducts with acetylenedicarboxylic acid upon photolysis in the presence of benzophenone.<77)... 

Esters of acetylenedicarboxylic acid 1023 are commercially readily available, are very reactive as dipolarophiles, and the carboxylic groups in products of their reactions can be easily converted to many other functionalities. Therefore, they are often the first choice as substrates for 1,3-dipolar cycloaddition to azides 1024 (Huisgen reaction). The reactions are carried out at room or elevated temperature, and the yields of 1,2,3-triazoles 1025 are usually high to quantitative (Equation 22). Several products obtained in this way are presented as structures 1026-1034. Some details about the reactions leading to these products are given in Table 10. 

Acetylenedicarboxylic acid, dimethyl ester, 50, 25, 36 Acetylenes, reaction with tri-methylsilyl azide, 50, 109 Acetylenic sulfonium salts, furans from, 53, 3 2-Acetylindane-l,3-dione, 52, 4 2-ACETYL-6-METHOXYNAPHTHALENE, 53, 5... 

Further studies on 1,3-dipolar addition reactions of diazophosphonates have been recorded,122 and work on 2-diazo-l-hydroxyalkylphosphonates also continues.123 The ester (155 R = H) reacts with esters of acetylenedicarboxylic acid without liberation of nitrogen to give stereoisomeric C-phosphorylated pyrazolines, which can be decomposed with both phosphorus-carbon and carbon-carbon bond fission, affording mixtures containing dimethyl acetylphosphonate, dimethyl hydrogen phosphonate, and tri(alkoxycarbonyl)pyrazolines. In the reaction between the same diazophosphonate and diazomethane, the latter conceivably acts as a basic catalyst for proton transfer in a series of steps which includes phosphonate-phosphate isomerization. The importance of a labile proton is demonstrated by the fact that the ester (155 R = Me) does not react in the manner described above. 

Acetylenedicarboxaldehyde, 1403 Acetylenedicarboxylic acid, 1405 Azido-2-butyne, 1473 3-Azidopropyne, 1114 Benzyloxyacetylene, 3133... 

Acetohydrazide, 0912 Acetone oxime, 1258 Acetylenedicarboxylic acid, 1405 Acrylaldehyde, 1145 f Allyl acetate, 1912 A-Ally lthiourca. 1600 4-Aminophenylazobenzene, 3487 Ammonium dichromate, 4246 Ammonium peroxodisulfate, 4576 4-Azidobenzaldehyde, 2697 2-Azido-2-phenylpropane, 3159 f Aziridine, 0863 Azobenzene, 3483 Azoformamide, 0816 Azoisobutyronitrile, 3011 Azoxybenzene, 3485 Benzaldehyde oxime, 2760... 

Dihydronaphthalen-1,4-iwmes from Isoindoles The naphthalen-l,4-imine derivatives 91-99 have been obtained by addition of acetylenedicarboxylic esters to the appropriate isoindoles. 3- ss Some such adducts react further with acetylenic esters (see Sections III, G and H), so that A -ethyl- and A-n-butylisoindole give 1 2 adducts with dimethyl aoetylenedicarboxylate instead. iV-Methylisoindole appears to be exceptional in giving an oily 2 1 adduct, for which structure (100) was suggested on analogy with the 2 1 adduct obtained from l,3-diphenylbenz[c]furan and acetylenedicarboxylic acid. ... 

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