Diethyl acetylenedicarboxylate

Vinyl ethers undergo many cycloaddition reactions similar to those which take place with enamines. In general, however, these cycloaddition reactions with vinyl ethers take place less readily than those with enamines. These reactions include cycloaddition of vinyl ethers with ketene (200-205), phenyl isocyanate (206), sulfene (207,208), methyl acrylate (209), diethyl acetylenedicarboxylate (210), and diphenylnitrilimine (183). 

Further investigations revealed that the disubstituted indolo[3,2-fl]carbazoles 117a-b may be conveniently obtained in moderate yields simply by heating 115 with dimethyl or diethyl acetylenedicarboxylate in xylene, while the use of lower-boiling solvents (benzene, toluene) led to the formation of the presumed intermediate Michael adducts 118a-b as the major products. The reaction of 115 with 2-chloroacrylonitrile furnished the indolo[3,2-fl]carbazole derivative 119 where aromatizaticRi did not take place (99T2371). 

Reaction of cyanothioformanilide 160 with diethyl acetylenedicarboxylate 161 gives a bispyrrolopyrazine product 162 (Equation 39) <2000PS(160)141>. 

Treatment of 3-(2-pyrrolidino)pyridine with 2 molar equiv of diethyl acetylenedicarboxylate under microwave conditions gives the tetrahydropyrrolonaphthyridine 283 and (presumably) diethyl maleate or fumarate. Under conventional heating conditions, decarboxylated products are also observed (Scheme 71) <2005TL3953>. 

Diethyl azodicarboxylate is usually abbreviated to DEAD. However, the same abbreviation is used for diethyl acetylenedicarboxylate. To avoid confusion, it is proposed that DEAZD should be used to abbreviate the azo ester. Similarly, DMAZD will be used for the dimethyl ester. Recently, the abbreviation DAZD has also been suggested B, M. Jacobson, D. Gerhard, C. Jackson, and J. Smallwood, J. Org. Chem. 45, 3344 (1980). 

The Alder-Bong reaction of cyclohexene with diethyl acetylenedicarboxylate 6 in DMF under reflux (Scheme 4.6) gives a 14% yield of the tricyclic compound 10 in... 

Scheme 4.4 Reaction of 1,4-di-phenylbutadiene with diethyl acetylenedicarboxylate...

Some new observations were published on the peculiar reactivity of the phenyloxazolopiperidine 166 which acts as an equivalent of an enamine, reacting with methyl vinyl ketone in a Michael reaction and with diethyl acetylenedicarboxylate in a [2+2] cycloaddition reaction <00JOC3209>. 

Diethyl acetylenedicarboxylate as di-eneophile, 40, 86,87 Diethylamine, condensation with tri-chloroacetyl chloride, 41, 21 Diethyl aminomalonate, from reduction of diethyl isonitrosomalonate, 40, 24... 

A recent method for the synthesis of the indolizine skeleton is represented by a three-component reaction between a-bromo ketones 16, pyridine 17, and ethyl propiolate or diethyl acetylenedicarboxylate. These three reagents, under microwave irradiation and catalysis by basic alumina, afforded a good variety of 3-aroyl indolizines 18 <20030L435> (Scheme 4). 

Details have appeared39 of the addition of PH-tetraoxyspirophosphoranes to aldehydes and activated ketones. These phosphoranes also add to activated acetylenes,40 e.g. diethyl acetylenedicarboxylate with (50) gives a mixture of cis- and trans-(51). Further addition of (50) to (51) at higher temperatures gives the bisphos-phorane (52). Metallation of the spirophosphorane (53) followed by reaction with... 

Additionally, uracil 6-iminophosphorane, isocyanate, and o-methyl-e-caprolactim ether join to form the intensely yellow pyrimido[4 5 4,5] pyrimido[6,l-n]azepine (360), as shown in Scheme 130. Upon ring closure, methanol is spontaneously eliminated. Diethyl azodicarboxylate affords with the other components pyrimido[4,5-e][l,2,4]triazoline (361), which is closely related to the alkaloid isofervenuline. The imidazo[5, -/][ ,2,4]tria-zine (362) results in a known Michael-type rearrangement sequence by treatment with diethyl acetylenedicarboxylate (86JOC149, 86JOC2787) in this latter case, the Michael-type addition occurs much faster than the expected three-component reaction [93H(35)1055]. 

Contrarily, diethyl acetylenedicarboxylate (276b) with quinaldine gives far fewer isolable products than does the dimethyl ester it affords no quinolizine but instead actually gives pyridoazepine 284 and cyclobu-taindolizine 281b. 

Di(3 -buten-1 -ynyl)cyclobutane, 3509 Dibutyl-3-methyl-3-buten-l-ynlborane, 3618 Diethyl acetylenedicarboxylate, 2987... 

Dichlorobenzo quinone -4-chloroimide Diethyl acetylenedicarboxylate Dimethyl 2-chloro-4-nitrophenyl thionophosphate Dimethyl 3-chloro-4-nitrophenyl thionophosphate Dimethyl 4-nitrophenyl thionophosphate A,A-Dimethyl-4-nitrosoaniline, Acetic anhydride. Acetic acid t Dimethyl sulfoxide... 

Several substituted hydroxy amines have been treated with acetylenic esters to give different heterocyclic systems. Thus, the reaction of o-aminophenol with diethyl acetylenedicarboxylate gives 3-carbethoxy-methylene-3,4-dihydro-2i/-l,4-benzoxazin-2-one (24) [Eq. (8)]. In... 

Diaziridines 96a and 96b react with diethyl acetylenedicarboxylate to yield oily products, presumed to be 97a and 97b. These have been characterized by hydrolyzing them to the known pyrazolinones 98a and 98b, respectively [Eq. (17)]. A similar observation has been made in the reaction of l-methyl-3,3-pentamethylenediaziridine (96b) with ethyl propiolate. The reaction of 3,3-pentamethylenediaziridine with ethyl propiolate, on the other hand, yields a simple 1 1 Michael adduct. ... 

The reaction of several thiophenols containing suitably positioned functional groups with acetylenic esters give rise to several interesting products. The reaction of pentafluorothiophenol with diethyl acetylenedicarboxylate in the presence of butyl lithium yields 2,3-dicarbethoxy-4,5,6,7-tetrafluorobenzol/>]thiophene (353), formed by... 

Diphenylphosphine oxide reacts with diethyl acetylenedicarboxylate to give a 2 1 adduct (460), and it has been suggested that in this reaction the phosphine oxide reacts in the tervalent form [Eq. (68)]. On the... 

With diethyl acetylenedicarboxylate the adduct formed can be ring opened by base treatment to afford diethyl 3-hydroxyphthalate (3-hydroxybenzene-l,2-dicarboxylate) (Scheme 6,27b). 

Q Suggest a reaction sequence whereby furan reacts with diethyl acetylenedicarboxylate to form a compound that can be partially hydrogenated and healed to give ethene and 3.4-bis(ethoxycar-bony )furan. 

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