Diphenyl-dimethyl-dicarboxylate

Kim YS, Kim DH, Kim DO, Lee BK, Kim KW, Park JN, Lee JC, Choi YS, Rim H. The effect of diphenyl-dimethyl-dicarboxylate on cyclosporine-A blood level in kidney transplants with chronic hepatitis. Korean J Intern Med ( 991) 12,67-9. 

In the case of 1,3-diphenylisoindole (29), Diels-Alder addition with maleic anhydride is readily reversible, and the position of equilibrium is found to be markedly dependent on the solvent. In ether, for example, the expected adduet (117) is formed in 72% yield, whereas in aeetonitrile solution the adduet is almost completely dissociated to its components. Similarly, the addition product (118) of maleic anhydride and l,3-diphenyl-2-methjdi.soindole is found to be completely dissociated on warming in methanol. The Diels-Alder products (119 and 120) formed by the addition of dimethyl acetylene-dicarboxylate and benzyne respectively to 1,3-diphcnylisoindole, show no tendency to revert to starting materials. An attempt to extrude carbethoxynitrene by thermal and photochemical methods from (121), prepared from the adduct (120) by treatment with butyl-lithium followed by ethyl chloroform ate, was unsuccessful. 

Highly substituted dimethyl 2,4-diphenyl-3-benzoxepin-l,5-dicarboxylate was converted by irradiation to an indene derivative 4 which had lost one benzoyl group by acidic hydrolysis.146... 

Subsequently, dimethyl 3,6-diphenyl-l-tosyl-l//-azepine-4,5-dicarboxylate was shown by HNMR spectral studies to be a 97 3 azepine/benzene imine 6/7 mixture at room temperature.71... 

J 7i-Cycloadducts at the C4 — C5 azepine positions are also formed with 1,2,3,4-tetra-chloro-5,5-dimethoxycyclopentadiene260 261 and with hexachlorocyclopentadiene.261 The reactivity of ethyl l//-azepine-l-carboxylate towards cyclopentadienones has been studied in terms of frontier molecular orbital theory which predicts that dimethyl 2-oxo-4,5-diphenyl-cyclopenta-1 (5),3-diene-1,3-dicarboxylate (20) should be more reactive towards the 1/f-azepine than other more common cyclopcntadienone derivatives.262 In fact, in refluxing benzene, the cyclopentadienone and ethyl 1/f-azepine-l-carboxylate (1) form a mixture of the [4 + 2] n-endo,anti-adduct 22, produced by Cope rearrangement of the initially formed [2 + 4] 7T-adduct 21, and the c.w-adduct 23, a rare example of a [6 + 4] rc-cycloadduct. At room temperature, only the [6 + 4] adduct 23 and a small amount of the [2 + 4] adduct 21 are obtained, the latter rearranging to the [4 + 2] adduct 22 on warming.262 Other [4 + 2] 7r-adducts with cyclopentadienones have been prepared similarly.263... 

Dimethyl 4,8-diphenyl-l,2,5,6-tetrazocine-3,7-dicarboxylate (3, vide supra) can be saponified and dccarboxylated in excellent yield.18... 

Dimethyl diphenyl sulfone 4,4 -dicarboxylate, s29 Dimethyleneimine, el48 Dimethylene oxide, el46... 

Pyrimidine ort o-quinodimethanes can also be produced from 5,6-dihydrocyclobuta[,y pyrimidine precursors <1997TL4873, 2002MOL507, 2006LOC703>, and in the case of the 2,4-diphenyl example 905, trapping of the intermediate 906 with dimethyl acetylenedicarboxylate was accompanied by aromatization to give dimethyl 2,4-diphenylquinazoline-6,7-dicarboxylate 907 in 50% yield <2002MOL507>. 

From the reaction mixture of l,3-diphenyl-l,2,3,4-tetrahydro-llbH-s-triazino[2,l-a]isoquinoline-2,4-dione (356) and dimethyl acetylenedicar-boxylate and dipheny ketene, dimethyl l-phenyl-2-oxo-l,llb-dihydro-2//-pyrimido[2,l-a]isoquinoline-3,4-dicarboxylate (64) and 1,3,3-triphenyl-l,3,4,llb-tetrahydro-2//-pyrimido[2,l-a]isoquinoline-2,4-dione (68), respectively, were isolated with other products (67CB1107). 

The number of 1,2,4,5-tetrazines used in these cycloaddition reactions is limited. The most frequently used are the 3,6-dicarboxylates, the 3,6-diphenyl, 3,6-dimethyl, 3,6-di(2-pyridyl) and bis(perfluoroalkyl) compounds a few others have also been used. The most reactive substances seem to be the 1,2,4,5-tetrazinedicarboxylates, possessing the extra electron-withdrawing effect of the two carboxylate groups. 

The following procedure represents a convenient preparative method leading to the synthesis of copper(I) pyrazolates, namely, [Cu(pz)]n (Hpz = IH-pyrazole), [Cu(dmpz)]3 (Hdmpz = 3,5-dimethyl-lH-pyrazole), [Cu(dcmpz)] (Hdcmpz = dimethyl- lf/-pyrazole-3,5-dicarboxylate), [Cu(dctpz)]n (Hdctpz = di-ferf-butyl-1 f/-pyrazole-3,5-dicarboxylate), and [Cu(dppz)]4 (Hdppz = 3,5-diphenyl-lH-pyrazole). In all cases, high yields ( >90%) of the pure products are obtained. 

Earlier, it had been reported that the reaction of benzoin with DMAD gives dimethyl 4,5-diphenyl-4-hydroxy-A2-dihydrofuran-2,3-dicarboxylate (3 23).43 The furan derivative (324) is formed on treatment of 323 with acid. Subsequent investigations have shown that a mixture... 

In order to confirm the stmcture of the tricyclic thietane 60, it underwent several reactions <20040L1313>, which were performed on the substituent of the ring carbon atom. The thietane 60 underwent hydrogenation on palladium-on-charcoal to give the fully saturated compound 61. The presence of a double bond in compound 60 was also confirmed by [4+2] Diels-Alder cycloaddition of dimethyl l,2,4,5-tetrazine-3,6-dicarboxylate as well as of diphenyl-isobenzofuran, which led to the formation of cycloadducts 62 and 63, respectively (Scheme 10) <20040L1313>. 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

The adduct 32 of diphenylcyclopropenethione to the morpholine enamine of acetophenone reacts with dimethyl acetylenedicarboxylate to yield a mixture of 1,2-diphenyl cyclopropene and dimethyl 4-morpholino-3-phenylthiophene-1,2-dicarboxylate (equation 21)41. 

Pyrrolidine Synthesis. The lithium (Z)-enolate of methyl iV-benzylideneglycinate undergoes a cycloaddition rapidly at —78°C with methyl (4J ,5R)-( )-3-( 1,3-dimethyl-4,5-diphenyl-2-imidazolidinyl)propenoate (1) to give pyrrolidine-2,4-dicarboxylate in quantitative yield and as a single stereoisomer (eq 1). Removal of the chiral auxiliary from the cycloadduct can be readily performed by treatment with cone Sulfuric Acid in MeOH at rt to produce the optically pure pyrrolidine-2,4-dicarboxylate bearing an acetal substituent at the 3-position. 

The same carbene can also be generated by thermolysis of 2,2-diphenyl-5-diphenyl-methylene-2,5-dihydro-l,3,4-oxadiazole. When the reaction was carried out in the presence of either dimethyl ( )-but-2-enedioate or dimethyl (Z)-but-2-enedioate one cyclopropane, dimethyl 3,3-diphenylcyclopropane-tranj-l,2-dicarboxylate (1), was formed, most likely via a 4,5-dihydro-3//-pyrazole intermediate. ... 

In the case of 3-aryl-substituted 3//-pyrazoles [e.g. dimethyl 3,3-diphenyl-3//-pyrazole-4,5-dicarboxylate (7)] indene formation often competes with formation of the cycloprop-... 

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