2- -4 -pyrido


The related 2-(4 -pyridyI)ethyl ester has also been prepared from the acid chloride and the alcohol.  [c.244]

The conversion of sedimentary organic matter into petroleum is termed maturation. The resulting products are largely controlled by the composition of the original matter. Figure 2.4 shows the maturation process, which starts with the conversion of mainly kerogen into petroleum but in very small amounts below a temperature of 50°C (kerogen organic rich material which will produce hydrocarbon on heating). The temperature rises as the sediment package subsides within the basinal framework. The peak conversion of kerogen occurs at a temperature of about 100°C. If the temperature is raised above 130°C for even a short period of time, crude oil itself will begin to crack and gas will start to be produced. Initially the composition of the gas will show a high content of C4 to C10 components ( Vi/et gas and condensate), but with further increases in temperature the mixture will tend towards the light hydrocarbons (C1 to C3, dry gas ). For more detail on the composition of hydrocarbons, refer to Section 5.2.  [c.12]

Figure A3.14.7. Example oscillatory time series for CO + O2 reaction in a flow reactor corresponding to different P-T locations in figure A3,14,6 (a) period-1 (b) period-2 (c) period-4 (d) aperiodic (chaotic) trace (e) period-5 (1) period-3. Figure A3.14.7. Example oscillatory time series for CO + O2 reaction in a flow reactor corresponding to different P-T locations in figure A3,14,6 (a) period-1 (b) period-2 (c) period-4 (d) aperiodic (chaotic) trace (e) period-5 (1) period-3.
The zeroth-order Hamiltonian and the spin-orbit part of the perturbation are diagonal with respect to the quantum numbers K, E, P, Uj, It, Uc, and Ic-The terms of H involving the parameters aj, ac, and bo aie diagonal with respect to both the Ij and Ic quantum numbers, while the f>2 term connects with one another the basis functions with I j = Ij 2, 4- 2. The c terms  [c.539]

The right-hand side of the form gives the network map in the upper part and to its right the simulated IR spectrum is plotted, which can be downloaded as a JCAMP File (cf. Section 2,4.5, Section 4,2,4.2). By clicking on tbe neurons in the map one obtains the RDF code and the spectrum of the corresponding structure in the lower part of the form and compared with those of the winning neuron,  [c.532]

Precautions, (i) The above tests must be carried out with discretion. If the substance is only moderately soluble in the solvent selected, and a comparatively large volume of the latter is required, the consequent dilution of the acid in the reagent may cause the separation of the free 2,4 dinitrophenylhydrazine (although this is more likely to happen with Reagent B than with A). Furthermore, if the compound under investigation should have basic properties, the neutralisation of part of the acid in the reagent may have the same result.  [c.264]

Several chemical methods have been devised for identifying the N terminal ammo acid They all take advantage of the fact that the N terminal ammo group is free and can act as a nucleophile The a ammo groups of all the other ammo acids are part of amide linkages are not free and are much less nucleophilic Sanger s method for N terminal residue analysis involves treating a peptide with 1 fluoro 2 4 dimtrobenzene which is very reactive toward nucleophilic aromatic substitution (Chapter 23)  [c.1131]

Of the adjustable parameters in the Eyring viscosity equation, kj is the most important. In Sec. 2.4 we discussed the desirability of having some sort of natural rate compared to which rates of shear could be described as large or small. This natural standard is provided by kj. The parameter kj entered our theory as the factor which described the frequency with which molecules passed from one equilibrium position to another in a flowing liquid. At this point we will find it more convenient to talk in terms of the period of this vibration rather than its frequency. We shall use r to symbolize this period and define it as the reciprocal of kj. In addition, we shall refer to this characteristic period as the relaxation time for the polymer. As its name implies, r measures the time over which the system relieves the applied stress by the relative slippage of the molecules past one another. In summary.  [c.98]

Figure 9.24 shows part of the laser Stark spectrum of the bent triatomic molecule FNO obtained with a CO infrared laser operating at 1837.430 cm All the transitions shown are Stark components of the rotational line of the Ig vibrational transition, where Vj is the N-F stretching vibration. The rotational symbolism is that for a symmetric rotor (to which FNO approximates) for which q implies that AA = 0, P implies that A/ = — 1 and the numbers indicate that K" = 7 and J" = 8 (see Section 6.2.4.2). In an electric field each J level is split into (J + 1) components (see Section 5.2.3), each specified by its value of Mj. The selection mle when the radiation is polarized perpendicular to the field (as here) is AMj = 1. Eight of the resulting Stark components are shown.  [c.369]

In general, the above boundary conditions hold provided that (2.141) is fulfilled and the solution is quite regular. In fact, some part of the boundary conditions can be considered as holding in the strong sense without any additional assumptions on regularity. In particular, as proved in Section 2.4,  [c.113]

U.S. plastics production in 1993 was about 70 biUion pounds (1). Plastics recycling continues to increase from its current value of 3.5% in the U.S. (2,4). However, recycling rates of some packaging products are much higher than this. The recycling rate of PET from soft drink bottles was 42% in 1993 while that of HDPE from milk and water jugs was 24% (2). This translates to 448 million pounds of PET and 450 million pounds of HDPE (1). Eor example, the process cost of recycling PET and HDPE bottles has been given as U.S. 100—150 per ton (71). The value of the PET and HDPE produced from recycled materials is U.S. 470 and U.S. 120 per ton, respectively. These recycling processes can be profitable. The favorable economics of PET recycling have been attributed in part to forward integrated PET recyclers consuming their own product to make bottle resin (24).  [c.233]

Mefluidide. N-[2,4-Dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]-acetamide [53780-34-0] (Mefluidide) (34) was the outcome of a synthetic program strongly oriented to the manufacture of A/-aryl-I,I,I-trifluoromethanesulfonamides. The compound has been evaluated under several experimental situations to control seed head formation in grass and to improve protein, sugar, and digestibiHty. It has also been used to increase sucrose levels in sugarcane and is appHed at the time that the cane matures (37). However, this is generally done in specific geographical areas, ie, Brazil, and it should be understood that a large percentage of the BraziHan sugar crop is converted to ethanol for motor fuel (see Alcohol fuels) (51) and pesticide residues are not a problem. For the most part, mefluidide is used to regulate the growth of turf in pubHc and commercial lands. It is a growth inhibitor and should be appHed to grass at the height that is aesthetically appealing to the eye. The compound may be appHed one day after mowing or the grass may be mowed three to seven days after appHcation (10). Mefluidide inhibits the growth of the meristems and therefore probably inhibits mitosis or ceU elongation. It is degraded into numerous metaboHtes which are biologically insignificant (10). Its life in the soil is short the half-life is two days. Photo decomposition proceeds rapidly on wet soil surfaces but the element of moisture is critical for this reaction. In cow and sheep experiments, using radio labeled mefluidide, it has been shown that neither milk nor meat are affected (52).  [c.425]

Hemicellulose [9034-32-6] is the least utilized component of the biomass triad comprising cellulose (qv), lignin (qv), and hemiceUulose. The term was origiaated by Schulze (1) and is used here to distinguish the nonceUulosic polysaccharides of plant cell walls from those that are not part of the wall stmcture. Confusion arises because other hemicellulose definitions based on solvent extraction are often used in the Hterature (2—4). The term polyose is used in Europe to describe these nonceUulosic polysaccharides from wood, whereas hemicellulose is used to describe the alkaline extracts from commercial pulps (4). The quantity of hemicellulose in different sources varies considerably as shown in Table 1.  [c.29]

Carcinogenicity. The public health implications of drinking water contamination by herbicides are unclear. The levels that have been detected in groundwater are generally in the part per billion (ppb) or part per trillion (ppt) range and are below estimated acute toxicity levels. However, the long-term health effects of this exposure are generally unknown. Several studies have demonstrated that the mortality from some types of cancer is significantly higher in mral residents of many com belt states (273). This trend is particularly evident in a study from Kansas involving 2,4-D exposure  [c.48]

Dentistry. Mercury is used in dental amalgams for fillings in teeth (see Dental materials). Dental uses have accounted for 2—4% of total U.S. mercury consumption since 1980 and generally 3—6% before that time (3). Dental amalgams used to fill cavities in teeth are approximately 50% mercury by weight. Dental use of mercury can be expected to continue to decrease, in part because of more effective cavity prevention as well as development and increasing use of alternative dental materials such as plastics and ceramics, and increasing awareness of the environmental and health effects of mercury.  [c.109]

Graphic Arts. Carbonless copy paper with global aimual sales well in excess of 5 biUion is by far the largest single commercial appHcation of microcapsules (2,4). This product consumes thousands of tons of capsules aimuaHy. Figure 10, a schematic diagram of a three-part business form, illustrates the concept of carbonless copy paper. The bottom surface of the top sheet of this form (sheet A) and the second sheet (sheet B) is coated with a layer of microcapsules that have a diameter of 3—6 p.m. The coating includes inert spacer particles that are larger than the microcapsules. They are often starch particles added to protect the microcapsules from premature mpture. The capsules, filled with a colorless solution of 2—6% leuco dye dissolved in a high boiling organic solvent, mpture under pressures encountered in normal handwriting or impact printing. The dye solution released is transferred from the bottom surface of sheets A and B to the top surface of sheets B and C, respectively, where it reacts to form an image. The reactive coating on the top surface of sheets B and C originally was attapulgite clay (see Clays). The use of a phenoHc resin, sahcyhc acid attapulgite clay, or acid-treated montmorillonite is favored. Any material that contains sufficient acidic sites to generate a color reaction and form a light-stable image could be used. Sheet A in Figure 10 is called a coated back (CB) sheet sheet B, a coated front back (CFB) sheet and sheet C, a coated front (CF) sheet. The capsules and reactive coating can be coated on the same paper surface. In this case, the product is called self-contained carbonless copy paper.  [c.323]

In addition to sections 1, 2, 4, and 6 of the General Standards for the Labeling of Prepackaged Eoods (Ref. No. CAC/RS 1-1969), the foUowing specific provisions apply. The name of the product shaH be "Evaporated milk," "Evaporated whole milk," "Evaporated fuU cream milk," "Unsweetened condensed whole milk," "Unsweetened fuU cream condensed milk," "Evaporated skimmed milk," "Unsweetened condensed skimmed milk," "Sweetened condensed milk," "Sweetened condensed whole milk," "Sweetened fuU cream condensed milk," "Skimmed sweetened condensed milk," or "Sweetened condensed skimmed milk," as appropriate. Where milk other than cow s milk is used for the manufacture of the product or any part thereof, a word or words denoting the animal or animals from which the milk has been derived should be inserted immediately before or after the designation of the product, except that no such insertion need be made if the consumer would not be misled by its omission. In sweetened milks, when one or several sugars are used, the name of each sugar shaH be declared on the label (26).  [c.365]

Weapons materials from production reactors were accumulated during the Cold War period as a part of the U.S. defense program. Prominent were tritium, ie, hydrogen-3, having a of 12.3 yr, and plutonium-239, 1/2 = 2.4 X lO" yr. The latter constitutes a waste both as a by-product of weapons fabrication in a waste material called transuranic waste (TRU), and as an excess fissionable material if not used for power production in a reactor.  [c.228]

Group II consists of the enkephalins which come from the 267-aniino acid piecuisoi pro-enkephalin A [88402-54-4] (Fig. 2). This proteia contains four copies of Met-enkephalin, one copy of Leu-enkephalin, and the extended peptides Met-enkephalin-Arg -Phe (the last Met-enkephalin sequence ia Fig. 2) and Met-enkephalin-Arg -Gly -Leu (the fourth Met-enkephalin sequence ia Fig. 2) (25,26). AH of these products ate formed by trypsin-like cleavage between pairs of basic residues. The extended enkephalin peptides are further cleaved by carboxypeptidase E (27) to form authentic Met-enkephalin.  [c.446]

Figure B3.2.4. A schematic illustration of an energy-independent augmented plane wave basis fimction used in the LAPW method. The black sine fimction represents the plane wave, the localized oscillations represent the augmentation of the fimction inside the atomic spheres used for the solution of the Sclirodinger equation. The nuclei are represented by filled black circles. In the lower part of the picture, the crystal potential is sketched. Figure B3.2.4. A schematic illustration of an energy-independent augmented plane wave basis fimction used in the LAPW method. The black sine fimction represents the plane wave, the localized oscillations represent the augmentation of the fimction inside the atomic spheres used for the solution of the Sclirodinger equation. The nuclei are represented by filled black circles. In the lower part of the picture, the crystal potential is sketched.
Stir a mixture of 2-4 g. of powdered hydrazine sulphate, 18 ml. of water and 2-4 ml. of concentrated aqueous ammonia (sp. gr. 0-88), and add 4-6 g. (4 4 ml.) of benzaldehyde (free from benzoic acid) dropwise, with stirring, over a period of 30-60 minutes. Stir the mixture for a further hour, collect the solid by suction filtration and wash it with water. RecrystalUse from 8 ml. of rectified spirit. The 3 ield of benzalazine (yellow needles), m.p. 92-93°, is 3-6 g.  [c.722]

Fortunately, azachalcone derivatives (2.4a-g, Scheme 2.4) turned out to be extremely suitable dienophiles for Lewis-add catalysed Diels-Alder reactions with cyclopentadiene (2.5). This reaction is outlined in Scheme 2.4 and a large part of this thesis will be devoted to the mechanistic details of this process. The presence of a chromophore in 2.4 allows kinetic studies as well as complexation studies by means of UV-vis spectroscopy. Furthermore, the reactivity of 2.4 is such that also the  [c.49]

Precautiom. (1) The above tests must be carried out with discretion. If the substance is only moderately soluble in the solvent selected, and a comparatively large volume of the latter is required, the consequent dilution of the acid in the reagent may cause the separation of the free 2,4-dinitrophenylhydrazine (although this is more likely to happen with Reagent B than with A). Furthermore, if the compound under investigation should have basic properties, the neutralisation of part of the acid in the reagent may have the same result.  [c.264]

The stability of the various cumulenic anions depends to a large extent upon the nature of the groups linked to the cumulenic system. Whereas solutions of lithiated allenic ethers and sulfides in diethyl ether or THF can be kept for a limited period at about O C, the lithiated hydrocarbons LiCH=C=CH-R are transformed into the isomeric lithium acetylides at temperatures above about -20 C, probably via HC C-C(Li )R R Lithiated 1,2,4-trienes, LiCH=C=C-C=C-, are  [c.9]

In the flask were placed 0.50 mol of freshly distilled methyl propargyl ether (VIII-6, Exp. 7), 100 ml of dry diethyl ether and 1.5 g of finely powdered copper(I bromide. A solution of cyclohexylmagnesium chloride in 400 ml of diethyl ether, prepared from 0.75 mol of cyclohexyl chloride (see Chapter II, Exp. 2), was added from the dropping funnel over a period of 30-40 min. During this addiiton the temperature of the reaction mixture was kept between -10 and +5°C (a cooling bath of dry-ice and acetone should be used). A greyish brown precipitate or slurry was formed. After the addition, stirring was continued for a further 30 min without external cooling. Water (200 ml) was then added cautiously with vigorous stirring and cooling in an ice-bath. After the disappearance of the solid material, enough dilute (2-4 N) hydrochloric acid was added just to give clear layers. The aqueous layer was extracted three times with small portions of diethyl ether and the combined solutions were washed with concentrated ammonium chloride solution and subsequently dried over magnesium sulfate. The diethyl ether was removed by evaporation in a water-pump vacuum. Careful distillation of the remaining liquid afforded cyclohexylal lene, b.p. 55°C/17 mmHg, njj 1.4801, in 71-77% yield.  [c.159]

It was then poured into 1.5 1 of water, after which eight extractions with small portions of redistilled pentane (note 3) were carried out. The combined pentane extracts were washed four times with 200-ml portions of 2 N HCl and once with water and then dried over magnesium sulfate. The greater part of the pentane was distilled off at normal pressure (bath temperature not higher than 75°C) through a 30-cm Vigreux column. Distillation of the remaining liquid gave 2-ethynylselenophen, b.p. 58 C/17 mmHg, n 1.6212, in 56-63X yield (calculated on l,6-dichloro-2,4--hexadiyne).  [c.208]

Then followed a twenty-year period during which several laboratories contributed to the development of syntheses in the thiohydantoin series (54-63) but could not unambiguously solve the structural problem of the N-monosubstituted derivatives (64—67) until 1902, when Wheeler and Johnson (68) examining the structure of the two isomeric monophenyl-thiohydantoin proved the inability of acid hydrolysis to determine the location of the phenyl group either on the ring nitrogen (46) or on the exocyclic nitrogen (47). They demonstrated that the reaction proceeded via ring opening, to phenylthiohydanloi c acid (48), followed by ring closure leading to a mixture of two 2,4-diketotetrahydrothiazoles (49) and (50). They demonstrated that when chloroacetanilide was gently warmed  [c.18]

When the asymmetric carbon atoms in a chiral compound are part of a ring, the isomerism is more complex than in acyclic compounds. A cyclic compound which has two different asymmetric carbons with different sets of substituent groups attached has a total of 2 = 4 optical isomers an enantiometric pair of cis isomers and an enantiometric pair of trans isomers. However, when the two asymmetric centers have the same set of substituent groups attached, the cis isomer is a meso compound and only the trans isomer is chiral. (See Fig. 1.15.)  [c.47]

In LC, because the mobile phase is a liquid and the stationary one is a granular solid, viscosity limitations rule out the simple use of the long capillary columns found in GC. Short columns of 10-25 cm and 2-4 mm internal diameter are more usual in LC. It is difficult to force the mobile solvent phase through such columns, and high-pressure pumps must be used to get a reasonable flow rate — hence the name high-pressure liquid chromatography (HPLC). More recently, very narrow LC columns have become available, but these nanocolumn.s must be operated at very high pressure to force the mobile liquid phase through them. Typically, a liquid phase flow of some 1 to 2 ml/min at a pressure of 20 to 200 bar (300 to 3000 Ib/in ) is used. Very often the high-pressure part of the terminology is omitted, as in LC/MS rather than HPLC/MS  [c.250]

Figure 9.48 Part of the fluorescence excitation spectrum of 1,2,4,5-tetrafluorobenzene in a supersonic jet. (Reproduced, with permission, from Okuyama, K., Kakinuma, T, Fujii, M., Mikami, N. and Ito, M., J. Phys. Chem., 90, 3948, f986) Figure 9.48 Part of the fluorescence excitation spectrum of 1,2,4,5-tetrafluorobenzene in a supersonic jet. (Reproduced, with permission, from Okuyama, K., Kakinuma, T, Fujii, M., Mikami, N. and Ito, M., J. Phys. Chem., 90, 3948, f986)
S. A. Ballard, H. de ViFinch, B. P. Geyer, G. W. Heame, C. W. Smith, and R. R. Whetstone, World Petroleum Congress Proceedings of the 4th Congress, Tome, 1955 Sect. 4, Part C, pp. 141—154.  [c.129]

Abaca. The abaca fiber is obtained from the leaves of the banana-like plant (same genus) Musa textilis (banana family, Musaceae). The fiber is also called Manila hemp from the port of its first shipment, although it has no relationship with hemp, a bast fiber. The mature plant has 12—20 stalks growing from its rhizome root system the stalks are 2.6—6.7 m tall and 10—20 cm thick at the base. The stalk has leaf sheaths that expand iato leaves 1—2.5 m long, 10—20 cm wide, and 10 mm thick at the center the fibers are ia the outermost layer. The plant produces a crop after five years, and 2—4 stalks can be harvested about every six months.  [c.362]

High purity hexafluorozirconic acid and its salts are produced by Advance Research Chemicals of the United States, and Akita and Moritta of Japan. The technical-grade green-colored material is suppHed by Cabot Corp. of the United States. In 1993, the U.S. market for fluorozirconic acid was about 250,000 kg/yr the world market was less than 500,000 kg/yr. A principal part of this production is consumed by the wool, garment, and upholstery industries. The 1993 price varied between 2.4 to 6.6/kg depending on the quaUty and quantity required. Potassium fluorozirconate [16923-95-8], K ZrF, is commercially important the world market is about 750,000 kg/yr. The most important appHcation is as a fire-retardant material in the wool (qv) industry, for the manufacture of garments, upholstery for aeroplane industry, and children s clothes (see Flame retardants). The 1993 unit price was between 5.0 and 6.6/kg.  [c.263]

Endosulfan [115-29-7] (36) is the adduct of hexachlorocyclopentadiene and l,4-dihydroxy-2-butene which reacts subsequendy with SOCI2 to produce 6,7,8,9,10,10-hexachloro-l,5,5i7,6,9,9i7-hexahydro-6,9-methano-2,4,3-ben2odioxathiepia-3-oxide. The technical product is a brownish soHd (mp 70— 100°C, vp 1.3 mPa at 30°C) which consists of about four parts of a-isomer (mp 108°C, cis with regard to the sulfite group) and one part of the P isomer (mp 206°C, trans with regard to the sulfite group). The a-isomer, which is somewhat more iasecticidal, is slowly converted to the more stable P-isomer at high temperature, and both isomers are oxidized slowly to endosulfan sulfate [1031-07-8] (mp 181 °C). In acid media, both isomers form endosulfan diol [2157-19-9] (mp 203°C). The rat LD qS are 43, 18 (oral) and 130, 74 (dermal) mg/kg. Endosulfan is a broad-spectmm iasecticide for vegetables, fmits, and row crops. Unlike the other cyclodiene iasecticides, it is biodegradable by hydrolysis at the sulfite ester bonds.  [c.278]

Metals have influenced and have served as the unit of monetary exchange throughout many parts of the world for millennia. Metal price has a very significant influence on production patterns. Price drives metal exploration and development of new resources, and is the main factor in determining materials substitution. High metal prices stimulate exploration activities and new mine development, which in turn increase supply. High metal prices also encourage the search for substitutes, decreasing demand. The prices in constant 1987 dollars of selected metals are plotted in Figure 2 (4). Metal price fluctuations and cycles are controlled by numerous factors. For example, the price of aluminum (Fig. 2a) indicates supply shortages and a relatively high price during World War I, and a general price decrease following this period. This decreasing trend reflects, in part, improved metallurgical efficiencies and process innovations. The decrease in copper, 2inc, and nickel prices (Fig. 2b) after 1920 indicates the successful and widespread appHcation of sulfide ore flotation and advances in electrolytic processing. Swings in gold and silver price (Fig. 2c) since the early 1970s indicate free-market forces and global poHtical and economic effects following suspension of governmental price controls.  [c.159]

There has been increasing co-use of ISM bands by communications interests, technically under the condition that any interference that may result from co-existing ISM apphcations be accepted. Proposals to reallocate part of the ISM bands for communication purposes have been made and the ECC had proposed auctioning a part (2402—2417 MHz) of the 2.45 GHz ISM band for primary use under co-use conditions. The number of microwave ovens has grown enormously (ca 200 million as of 1995). The CISPR has therefore been studying new limits in the 1—18 GHz range in order to minimize interference with wireless communications systems expected to occupy allocations across the band from 1 to 3 GHz by the late 1990s. The resulting regulations are likely to have some impact on microwave oven and higher power equipment design because of the weU-known excess noise produced by magnetrons in sideband regions, ie, 2.2—2.4 and 2.5—2.7 GHz for a 2.45 GHz source (19).  [c.338]

Ligand-Modified Rhodium Process. The triphenylphosphine-modified rhodium oxo process, termed the LP Oxo process, is the industry standard for the hydroformylation of ethylene and propylene as of this writing (ca 1995). It employs a triphenylphosphine [603-35-0] (TPP) (1) modified rhodium catalyst. The process operates at low (0.7—3 MPa (100—450 psi)) pressures and low (80—120°C) temperatures. Suitable sources of rhodium are the alkanoate, 2,4-pentanedionate, or nitrate. A low (60—80 kPa (8.7—11.6 psi)) CO partial pressure and high (10—12%) TPP concentration are critical to obtaining a high (eg, 10 1) normal-to-branched aldehyde ratio. The process, first commercialized in 1976 by Union Carbide Corporation in Ponce, Puerto Rico, has been ficensed worldwide by Union Carbide Corporation and Davy Process Technology.  [c.467]


See pages that mention the term 2- -4 -pyrido : [c.198]    [c.267]    [c.260]    [c.90]    [c.1243]    [c.2212]    [c.2597]    [c.1032]    [c.24]    [c.208]    [c.426]    [c.45]    [c.453]    [c.337]   
Advances in heterocyclic chemistry Vol.85 (2003) -- [ c.2 ]