Furyl compounds

The special reagent used for the replacement of Sn(IV) by Pb(IV) is lead tetraacetate in the presence of mercury diacetate acting as a catalyst3678. The corresponding 2-furyl compounds can be prepared analogously ... 

An alternative route to furyl compounds of similar structure was reported by Yao et al. <2005BML511> the same starting amine 409 was N-aminated to the 1,2-diaminopyrazinium mesylate 412, which was ring-closed by treatment with furylaldehyde to yield 413 in rather poor yield. The synthesis of the pyrrolidinylcarbonyl derivative 415 in a cyclocondensation reaction of 414 by use of polyphosphoric acid was reported by Giardina et al. <1995FA405>. 

Photolysis of matrix isolated diazo(2-furyl)methane led to the aldehyde (79) by stereospecific rearrangement of the carbene (80). " The corresponding 3-furyl compound gave the (5-Z)-methylenecyclopropene (81) by ring closure of the initially formed vinylcarbene to give cyclopropene (82) followed by ring opening of the furan. 

Work on photochromic fulgides continues. The furyl compound (142) gives a ring-closed product in near quantitative yield on irradiation or on heating the reaction can be reversed using visible ( white ) light. This report also describes the... 

Furyl compounds (Fig. 2B) after exposure to long-wave ultraviolet (UVA, 300-400 nm) exhibit broad efficacy against viruses [7]. Several reports on the antiviral activity of furocoumarins (psoralens) and furanochromones (visna-gin) from Rutaceae and Umbelhferae (Apiaceae) are available [13]. The compounds require UVA for their activity and appear to inhibit virus replication by disrupting viral gene target expression by forming photo-adduct with the virus DNA. 

For example, when R = 2-thienyl, a 55% yield of (11) with R = 2-furyl, compound (11, R = 2-furyl) was obtained in 45% yield along with a 10% yield of the 1,4-addition product (10, R = 2-furyl). 

The Li compound 588 formed by the ort/io-lithiation of A. A -dimethylaniline reacts with vinyl bromide to give the styrene derivative 589(433]. The 2-phe-nylindole 591 is formed by the coupling of l-methyl-2-indolylmagnesium formed in situ from the indolyllithium 590 and MgBr2, with iodobenzene using dppb[434]. 2-Furyl- and 2-thienyllithium in the presence of MgBr2 react with alkenyl halides[435]. The arylallenes 592 and 1,2,4-alkatrienes are prepared by the coupling reaction of the allenyllithium with aryl or alkenyl halides[436]. 

Compound 129, with R=Ph, p-MeCsH4, p-MeOC H, p-EtOC H, and 2-furyl, was obtained in 70 to 80% yield when p-phenylene bis-thiourea was heated with iodine and p-AcCaHjE, accxtrding to Method B (741). 

Chemically, wood tar is a complex mixture that contains at least 200 individual compounds, among which the foUowing have been isolated (1) 2-methoxyphenol, 2-methoxy-4-ethylphenol, 5-meth5i-2-methoxyphenol, 2,6-x5ienol, butyric acid, crotonic acid, 1-hydroxy-2-propanone, butyrolactone, 2-methyl-3-hydroxy-4JT-pyran-4-one, 2-methyl-2-propenal, methyl ethyl ketone, methyl isopropyl ketone, methyl furyl ketone, and 2-hydroxy-3-methyl-2-cyclopenten-l-one. 

In many cases, substituents linked to a pyrrole, furan or thiophene ring show similar reactivity to those linked to a benzenoid nucleus. This generalization is not true for amino or hydroxyl groups. Hydroxy compounds exist largely, or entirely, in an alternative nonaromatic tautomeric form. Derivatives of this type show little resemblance in their reactions to anilines or phenols. Thienyl- and especially pyrryl- and furyl-methyl halides show enhanced reactivity compared with benzyl halides because the halogen is made more labile by electron release of the type shown below. Hydroxymethyl and aminomethyl groups on heteroaromatic nuclei are activated to nucleophilic attack by a similar effect. 

When in position 2 on a 2-pyridyl or 2-furyl ring, 4,9-oxo groups can be reduced and acylated the obtained compounds were active against streptococci and staphylococci (62GEP1). 

E) Preparation of 2-( 1-Succinyloxyethyl)-3-Methyl-5-(2-Oxo-2,5-Dihydro-4-Furyl)Bemo[b] -Furan (409 CBj 8.65 grams of compound 3574 CB in 43 ml of pyridine are warmed for 30 minutes, on a water bath, with succinic anhydride. At the end of this, the pyridine is stripped off in vacuo. The mixture is treated with dilute sulfuric acid and with ether, the crystalline product filtered off, washed with water and with ether, and recrystallized from ethyl acetate (9.35 grams). MPq = 144°C (measured after drying at 90°C and 0.1 mm). Yield 77%. The product yields an equimolecular compound with morpholine. MPc= 136°C (from ethyl acetate). 

Uvarova and Gorshkova131 reported the thermal polymerization of 2-furfuryl vinyl ether and of a series of vinyl ethers of alkyl-1-(2-furyl) eaibinols. Treatment of these compounds at 150 °C for 24 hours produced brown cross-linked products with 2-furfuryl vinyl ether, and soluble, low molecular-weight polymers with the others. It seems likely that in all these systems the ring participated in the growth of the chains, but the lack of experimental details and of structural determination makes it difficult to assess the results. 

Various heterocyclic compounds contribute particular flavor and aroma notes some examples follow Furfural is haylike,15 N-furyl pyrroles pos-... 

Eudy, L. W. Walla, M. D. Hudson, J. R. Morgan, S. L. Fox, A. Gas chromatog-raphy-mass spectrometry studies on the occurrence of acetamide, propionamide and furyl alchohol in pyrolysates of bacteria, bacteria fractions and model compounds. J. Anal. Appl. Pyrolysis 1985, 7, 231-247. 

The IMDAF (intramolecular Diels-Alder furan) precursors 492 were prepared via Michael addition of nucleophiles possessing an unsaturated tether 491 to furoyl nitroalkene 490. Furyl nitroalkene 490 was prepaperd via the nitroaldol (Flenry) reaction. Compound 492 was heated in appropriate solvent such as toluene, xylene, etc., to provide the IMDAF cycloadducts 65 and 66 (Table 16) <2005JOC2235>. 

The pyrido[3, 4 4,5]furo[3,2-A]indole 24 can be prepared by Curtius rearrangement of 3-[5-(2-nitrophenyl)-2-furyl]-propenoic azide 25, followed by reduction of the nitrophenyl functionality of the product 26, chlorination of the tetracyclic product (PCI5), then reduction (Zn/AcOH) to give the parent compound 24 <1987CCC192> (Scheme 7). 

Nitroheteroarenes continue to attract research activity. A series of 5-nitro-2-furyl derivatives were evaluated for in vivo efficacy against T cruzi [64] and an improved toxicity profile. Compound 65 showed a good efficacy profile in vivo and better acute toxicity profile when compared to nifurti-mox. A series of 5-nitroindazoles, represented by 66 (IC50 = 7.4 iM), were reported as having activity similar to nifurtimox (IC50 = 3.4 iM) in a growth inhibition assay [65]. 

Moreover, the compound (LV) obtained from the reaction of 2-keto-D-gluconic acid with o-phenylenediamine28 has been dehydrated to give a compound which Maurer erroneously described as LYI. In this case, also, the process of dehydration has been shown to be equivalent to that just described for compound L. The product obtained by interaction of 2-furyl-... 

Insertion of thienyl or furyl groups into alkyllead compounds can be carried out using organolithium reagents. Thus, organolead(IV) tricarboxylates can be prepared as follows via tin(IV) precursors ... 

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