Methanol thiophene

Diffraction data for the alkoxy-substituted materials are scarce. For PMEEMT x-ray diffraction patterns were recorded [44] at two temperatures, room temperature and 150°C, showing in both cases three to four rather broad peaks on a diffuse background. The peaks correspond to interplanar distance d= 17.8 A, 7.0 A, 3.8 A and 2.4 A, the latter two being close to two values also found for PATs as the 6-axis parameter and a diffuse feature at 0 = 2.6 A related to the main chain periodicity. It is remarkable that the diffraction pattern survives heating to 150"C, which is above the thermochromic transition for PMEEMT. A recent diffraction study of poly methanol-thiophene) prepared electrochemically showed only broad amorphous scattering around 0= 1.4 A [94],... 

Kudryavtseva, L. Eizen, O. Vapor-hquid equihbrium in the systems thiophene -nitromethane, methanol - thiophene tmd methyl ethyl ketone - thiophene [Russ] Zh. Prikl. Khim. (Leningrad) 1970,43,708-711... 

Toghiani, H. Toghiani, R. K. Viswanath, D. S. Vapor-liquid equilibria for the methanol-benzene and methanol-thiophene... 

Hossein Toghiani, Rebecca K. Toghiani, and Dabir S. Viswanath, Vapor-Liquid Equilibria for the Methanol-Benzene and Methanol-Thiophene Systems. / Chem. Eng. Data, 39, 63-67(1994). 

Idemitsu Process. Idemitsu built a 50 t x 10 per year plant at Chiba, Japan, which was commissioned in Febmary of 1989. In the Idemitsu process, ethylene is oligomerised at 120°C and 3.3 MPa (33 atm) for about one hour in the presence of a large amount of cyclohexane and a three-component catalyst. The cyclohexane comprises about 120% of the product olefin. The catalyst includes sirconium tetrachloride, an aluminum alkyl such as a mixture of ethylalurninumsesquichloride and triethyl aluminum, and a Lewis base such as thiophene or an alcohol such as methanol (qv). This catalyst combination appears to produce more polymer (- 2%) than catalysts used in other a-olefin processes. The catalyst content of the cmde product is about 0.1 wt %. The catalyst is killed by using weak ammonium hydroxide followed by a water wash. Ethylene and cyclohexane are recycled. Idemitsu s basic a-olefin process patent (9) indicates that linear a-olefin levels are as high as 96% at C g and close to 100% at and Cg. This is somewhat higher than those produced by other processes. 

Aminothiophenes and 3-aminobenzo[Z)]thiophene undergo thermal [2 + 2] cycloaddi-tion reactions with activated alkynes. The reactions are solvent dependent thus in non-polar solvents at -30 °C, 3-pyrrolidinothiophene adds to DMAD to give a [2 + 2] cycloadduct which is ultimately converted into a phthalic ester. In methanol, however, a tricyclic product is formed (Scheme 54) (81JOC424. ... 

Benzo[h]thiophene sulfone (229) reacts as a vinyl sulfone and forms adducts (228) and (230) when treated with mercury(II) acetate in methanol and with cyclopentadiene, respectively. 

A solution of 85.8 g (0.2 moles) of 3/ -acetoxy-27-norchoIest-5-en-25-one in 500 ml of anhydrous thiophen-free benzene is added to a Grignard solution prepared from 24.3 g (1 g-atom) of magnesium and 149 g (1.05 moles) of freshly distilled methyl iodide in 575 ml of anhydrous ether. The mixture is refluxed for 3 hr and allowed to stand overnight. After cooling to 5° the complex is decomposed by the slow addition of 200 ml of ice water and 400 ml of 50% acetic acid solution, and steam distilled until no more oil passes over. The residual product is filtered, washed with water and dried at 80°. Crystallization from methanol gives 70 g (87%) of cholest-5-ene-3)5,25-diol mp 179.5-181°. The analytical sample melts at 181.5-182.5° [a]o —39° (CHCI3). 

The halogens of halothiophenes are more labile than those of the corresponding benzenes in accordance with theoretical considera-tions which indicate that thiophenes should also undergo nucleophilic substitutions more rapidly than benzenes. Hurd and Kreuz" found that in qualitative experiments 3,5-dinitro-2-chlorothiophene was more reactive toward piperidine and methanolic potassium hydroxide than 2,4-dinitrochlorobenzene. A quantitative study on the reaction of the six isomeric bromonitrothiophenes with piperidine (Table V) shows that the thiophenes react about one thousand times... 

With sodium sulfide in methanol (pH = 9), deca-2,4,6,8-tetrayne (51) forms 5-methyl-(2-penta-2,4-diynyl)thiophene (52) in 60% yield (77HOU947). 

Chemical Name 0i-[4-(Diethylamino)cyclohexyl] -Q -2-thienyl-2-thiophene-methanol Common Name —... 

There have been very few examples of PTV derivatives substituted at the vinylene position. One example poly(2,5-thienylene-1,2-dimethoxy-ethenylene) 102 has been documented by Geise and co-workers and its synthesis is outlined in Scheme 1-32 [133]. Thiophene-2,5-dicarboxaldehyde 99 is polymerized using a benzoin condensation the polyacyloin precursor 100 was treated with base to obtain polydianion 101. Subsequent treatment with dimethyl sulfate affords 102, which is soluble in solvents such as chloroform, methanol, and DMF. The molar mass of the polymer obtained is rather low (M = 1010) and its band gap ( ,.=2.13 eV) is substantially blue-shifted relative to PTV itself. Despite the low effective conjugation, the material is reasonably conductive when doped with l2 (cr=0.4 S cm 1). 

Cleavage of the acetate unit(s) in 5-acetoxy- and 3,5-diacetoxy-4-phenyl-l-benzothiepins 11 with potassium carbonate in methanol at room temperature does not stop at the diketone stage, but further undergoes ring contraction to the thiophene derivative 12 in 55-80% yield.90... 

Preparation of Reactants. Reagent-grade, thiophene free benzene was stored over 4A molecular sieves and sodium ribbon in a helium atmosphere. Styrene was distilled to remove dissolved oxygen and moisture and stored under a helium atmosphere. Prior to use, styrene was injected into a copious quantity of methanol to determine if any polymerization had occurred. If there was... 

Thiophenes can also be desulfurized to alkenes (RCH2CH=CHCH2R from 115) with a nickel boride catalyst prepared from nickel(II) chloride and NaBILj in methanol.It is possible to reduce just one SR group of a dithioacetal by treatment... 

The reaction of the a-bromo aldoxime 52e (R = R = Me) with unsaturated alcohols has been extended to the heterocyclic systems furfuryl alcohols and 2-thiophene methanol [29b]. The furanyl and thiophenyl oximes 63a-c were treated with NaOCl and the resulting heterocyclic nitrile oxides were found to undergo spontaneous intramolecular dipolar cycloaddition to produce the unsaturated tricyclic isoxazolines 64a-c in high yield (Eq. 5). In these cases, the heterocyclic ring acts as the dipolarophile with one of the double bonds adding to the nitrile oxide [30]. 

The reaction of sulphides 59 bearing an ethynyl or a carbomethoxy group a to sulphur with f-butyl hypochlorite in methanol or ethanol gives high yields of the corresponding a-alkoxy sulphides (60) rather than sulphoxides (equation 29). Oxidation of benzo[b]thiophene with t-butyl hypochlorite in t-butyl alcohol at 30-40° gave the corresponding 2-chloro-l-benzothiophen-l-oxide 61 in 45% yield (equation 30). 

Such nucleophilic displacements are likely to be addition-elimination reactions, whether or not radical anions are also interposed as intermediates. The addition of methoxide ion to 2-nitrofuran in methanol or dimethyl sulfoxide affords a deep red salt of the anion 69 PMR shows the 5-proton has the greatest upfield shift, the 3- and 4-protons remaining vinylic in type.18 7 The similar additions in the thiophene series are less complete, presumably because oxygen is relatively electronegative and the furan aromaticity relatively low. Additional electronegative substituents increase the rate of addition and a second nitro group makes it necessary to use stopped flow techniques of rate measurement.141 In contrast, one acyl group (benzoyl or carboxy) does not stabilize an addition product and seldom promotes nucleophilic substitution by weaker nucleophiles such as ammonia. Whereas... 

When 3(4)-substituted thiophenes (e.g., 3-hexylthiophene) are used as monomers, the polymers are partly or completely soluble in low polar organic solvents like toluene, chloroform, dichloromethane, THF. Therefore, after washing with ethanol, the polymer is dried, then dissolved in chloroform and reprecipitated into methanol or acetone to remove low-molecular-weight fractions. The solid is collected by filtration, washed with methanol, and dried in vacuo. 

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