2.5- diaryl-4-methyl

Diaryl methyl- and benzyl-phosphonates are conveniently prepared in high yields by heating mixtures of triaryl phosphites, methanol or benzyl alcohol, and a trace of methyl or benzyl halide. In a reaction that is usefully complementary to the previously reported formation of pyridine-2-phosphonic acid derivatives from sodium dialkyl phosphonates and //-methoxypyridinium compounds ( Organophosphorus Chemistry , Vol. 7, p. 111), N-triphenylmethylpyridinium tetrafluoroborate affords the pyridine-4-phosphonic dialkyl ester when heated with sodium dialkyl phosphonates. ... 

Benzimidazoles. Further modification of the benzimidazol-one-moiety of oxatomide has led to the synthesis of a large number of benzimidazoles, which are summarized in Table II. These compounds were synthesized as outlined in Scheme 4. Cyclization of IX with the appropriate carboxylic acids or with the bisulphite complexes of the aldehydes gave benzimidazoles XI (9). Successive chlorination with thionylchloride and coupling with l-(a, a -diaryl-methyl)-piperazines (II) afforded the benzimidazoles XIII (R = H, alkyl, aryl, cycloalkyl, aralkyl). 

The photoinduced anti-Markovnikov addition of methanol to 1,1-diphenylethene reported by Arnold and co-workers in 1973 provides the first example of the addition of a nucleophile to an arylalkene radical cation. There are now a number of studies that demonstrate the generality of nucleophilic addition of alcohols, amines, and anions such as cyanide to aryl- and diaryl-alkene radical cations. Product studies and mechanistic work have established that addition occurs at the 3-position of I-aryl or 1,1 -diarylalkene radical cations to give arylmethyl or diaryl-methyl radical-derived products as shown in Scheme I for the addition of methanol to 1,1-diphenylethene. For neutral nucleophiles, such as alcohols and amines, radical formation requires prior deprotonation of the 1,3-distonic radical cation formed in the initial addition reaction. The final product usually results from reduction of the radical by the sensitizer radical anion to give an anion that is then protonated, although other radical... 

Several benzyhc cations have been obtained in solution as SbFg salts. Diaryl-methyl and triaryhnethyl cations are still more stable. Aryhnethyl cations are further stabihzed if they have electron-donating substituents in ortho or para positions. The stabihty of such cations can be further increased if electron-donating substituents feed into the it-system. Triaryknethyl cations are propeUer-shaped, even though the central carbon atom and the three ring carbons connected to it are in a plane. The three benzene rings cannot be all in the same plane because of steric hindrance. 

Scheme 22 Synthesis of chiral diaryl-methyl and alkyl-methylphenyl phosphine oxides 69...

Figure 4.5 shows NBMO coefficients for several arylmethyl, diaryl-methyl, and triarylmethyl radicals. It will be seen that the NBMO coefficients at the exocyclic carbon atoms decrease rapidly with the number of attached groups. Dissociation should therefore occur most readily in the case of hexaarylethanes. This is the case. Solutions of hexaphenylethane at room temperature contain free triphenylmethyl radicals, whereas tetraarylmethanes dissociate to an appreciable extent only at much higher temperatures and diarylethanes are still more stable. 

The catalytic reduction of 2-methyl-3-phenyl-3-isoxazoline (159) produced /3-hydroxypropiophenone (160) (74CPB70). Ring fission also occurred on base treatment of the 3,5-diaryl-3-isoxazoline (161) to give the a,/3-unsaturated oxime (162) (70CI(L)624). 

Hydantoin, 5,5-diaryl-2,4-dithio-methylation, 5, 444 Hydantoin, 1,3-divinyl-polymers, 1, 280 Hydantoin, 5-methylene-polymers, 1, 280 Hydantoin, 5-phenyl-2-thio-tautomerism, 5, 370 Hydantoin, thio-... 

Imidazolidin-2-one, l-(5-nitro-2-thiazolyl)-pharmacological activity, 6, 328 Imidazolidin-4-one, l-aryl-3-phenyl-2-thioxo- C NM S, 355 Imidazolidinones C NMR, 5, 355 Imidazolidin-2-ones nucleophilic displacement, 5, 428 polymers, 1, 279-280 reactivity, 5, 376 synthesis, 5, 466, 471 Imidazolidin-4-ones synthesis, 5, 468 Imidazoline, 2-alkyl-synthesis, 5, 463 Imidazoline, 2-amino-applications, 5, 498 Imidazoline, 2-aryl-synthesis, 5, 463 Imidazoline, 2-methyl-synthesis, 5, 487 Imidazoline, 2-nitroamino-synthesis, 5, 471 2-Imidazoline, 2-arylamino-tautomerism, 5, 368 2-Imidazoline, 1-benzyl-methylation, 5, 425 2-Imidazoline, 1,2-diaryl-synthesis, 5, 463... 

Indolizine, hydroxy-conformations, 4, 451 GLC retention times, 4, 451 synthesis, 4, 121 tautomerism, 4, 198, 452 Indolizine, 2-hydroxy-synthesis, 4, 463 Indolizine, 8-hydroxy-conformation, 4, 452 Indolizine, 2-hydroxymethyl-synthesis, 4, 461 Indolizine, 3-hydroxymethyl-synthesis, 4, 461 Indolizine, 6-hydroxymethyl-synthesis, 4, 461 Indolizine, methyl-mass spectra, 4, 187, 450 NM 4, 448 Indolizine, 2-methyl-diazo coupling, 4, 454 mass spectra, 2, 529, 4, 450 nitration, 4, 50, 454 nitrosation, 4, 454 reaction with diaryl disulfide, 4, 460 reaction with nitroethane, 4, 460 Indolizine, 3-methyl-basicity, 4, 454 Indolizine, 5-methyl-acidity, 4, 461 synthesis, 4, 466 Indolizine, 6-methyl-mass spectra, 4, 450 Indolizine, l-methyl-2-phenyl-nitration, 4, 454 nitrosation, 4, 454, 455 Indolizine, 3-methyl-2-phenyl-reaction... 

Pyrrole, 3,4-dialkyl-2-ethyl-5-methyl-benzoylation, 4, 220 Pyrrole, 1,2-diamino-reactions, 4, 300 Pyrrole, 2,5-diamino-tautomerism, 4, 200, 299 Pyrrole, 2,4-diaryl-nitration, 4, 210 Pyrrole, 2,5-diaryl-synthesis, 4, 343 Pyrrole, 3,4-diaryl-synthesis, 4, 343 Pyrrole, di-t-butyl-protonation, 4, 47 Pyrrole, 2,5-dichloro-synthesis, 4, 368... 

Thiirene, 2-acetyI-3-methyl-rearrangement, 7, 143 Thiirene, 2,3-bis(trifluoromethyl)-photolysis, 7, 142 Thiirene, 2,3-diaryl-... 

Vinyl Inflates permit alkylation with vinyl cations [24, 25] Fluorobenzene reacts with 2 methyl 1-phenyl 1 propenyl triflate to form a diaryl alkene [24J (equation 17)... 

Bromination of the methyl group of (249) with A -bromosuccinimide, followed by reaction with excess secondary amine gave (250) which shows combined analgesic and antitussive properties. The Reformatsky reaction has also been used for the preparation of 2-amino-ethyl 3,3-diaryl-3-hydroxypropanates (251) as well as their dehydration products. The propene amides (252) have also been prepared for pharmacological evaluation. In l-methyl-3-bis (2-thienyl)-... 

It must be taken into account that in all papers published between 1916 and 1922 the structure of methyldiarylpyrylium salts is erroneously indicated as a symmetrical 2,6-diarjd-4-methylpyrylium structure. The unsymmetrical structure (2,4-diaryl-6-methyl) was recognized by Gastaldi, then by Schneider and Ross, and finally by Dilthey and Fischer. ... 

Ethyl 6,7-diaryl-3-hydroxy-2-oxo-2,5-dihydro-l//-azepine-4-carboxylates, e.g. 20, with diazomethane methylate solely at the 3-hydroxy group, whereas with Meerwein s reagent the 7-ethoxy-4/7-azepines, e.g. 21, are formed.48... 

Kinetic studies of the oxidation of diaryl sulfoxides by Crvi led to the proposition of a single electron transfer67 as in the case of aryl methyl sulfoxides68. These reactions were performed in aqueous acetic acid/perchloric acid medium, HCr03+ being the active... 

Zur asymmetrischen Reduktion von Diaryl-ketonen mit (S)-Lithium-2-methyl-piperidid zu optisch akti-ven Alkoholen mit im wesentlichcn (/ )-(Configuration (Umsatz —50%) s. Lit.1. 

Hydroperoxy-2-methyl- 570 2-Hydroperoxy-2-phenyl- 570, 680 2-Hydroximino- 376, 613 2-Hydroximino-l-aryl- 379f 2-Hydroximino-l.3-diaryl- 379f. 

In the frame of a medicinal project at J J Pharmaceutical Research and Development aimed at designing new potent and selective glycogen synthase kinase-3/i (GSK-3/3) inhibitors, the C-3 derivatization of the 1-methyl-4-[l-alkyl-lff-indol-3-yl]-lff-pyrrole-2,5-dione scaffold was explored [31]. Microwave-assisted Stille reaction of 3-chloro-l-methyl-4-[l-alkyl-lff-indol-3-yl]-lH-pyrrole-2,5-diones with (2,4-dimethoxy-5-pyrimidinyl)(tributyl) stannane at 200 °C yielded in 6 min the desired 3,4-diaryl-lff-pyrrole-2,5-diones in moderate yields (Scheme 12). 

Organ et al. from York University demonstrated that a diarylated IH-pyrazole-based library, based on the structure of the potent COX II inhibitor Celecoxib [4-(3-trifluoromethyl-5-(4-methylphenyl)-lH-pyrazol-l-yl)benzenesulfonamide], could be rapidly prepared using MAOS [59]. Microwave-accelerated Suzuki reaction on 4-(5-iodo-3-methyl-lH-pyrazol-l-yl)-benzenesulfonamide using heterogeneous Pd/C was the principal diversification step investigated (Scheme 41). The interest of the team in microwave... 

The reaction of diazo compounds with amines is similar to 10-15. The acidity of amines is not great enough for the reaction to proceed without a catalyst, but BF3, which converts the amine to the F3B-NHR2 complex, enables the reaction to take place. Cuprous cyanide can also be used as a catalyst. The most common substrate is diazomethane, in which case this is a method for the methylation of amines. Ammonia has been used as the amine but, as in the case of 10-44, mixtures of primary, secondary, and tertiary amines are obtained. Primary aliphatic amines give mixtures of secondary and tertiary amines. Secondary amines give successful alkylation. Primary aromatic amines also give the reaction, but diaryl or arylalkyl-amines react very poorly. 

This reaction is similar to 13-1 and, like that one, generally requires activated substrates. With unactivated substrates, side reactions predominate, though aryl methyl ethers have been prepared from unactivated chlorides by treatment with MeO in HMPA. This reaction gives better yields than 13-1 and is used more often. A good solvent is liquid ammonia. The compound NaOMe reacted with o- and p-fluoronitrobenzenes 10 times faster in NH3 at — 70°C than in MeOH. Phase-transfer catalysis has also been used. The reaction of 4-iodotoluene and 3,4-dimethylphenol, in the presence of a copper catalyst and cesium carbonate, gave the diaryl ether (Ar—O—Ar ). Alcohols were coupled with aryl halides in the presence of palladium catalysts to give the Ar—O—R ether. Nickel catalysts have also been used. ... 

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