Phthalic residue

As regards the chemical structure effect, it clearly appears that replacing the zso-phthalic residue by a tere-phthalic one, considerably increases the temperature range in which SDZs exist. In contrast, the length of the lactam-12 unit does not have any effect. It is worth noting that an opposite influence between the nature of the phthalic group and the length of the lactam-12 unit happens for Tn-... 

The crude phthalic anhydride is heated and held at 260 C to allow some byproduct reactions to go to completion. Purification is by continuous distillation in two columns. In the first column, maleic anhydride and benzoic and toluic acids are removed overhead. In the second column, pure phthalic anhydride is removed overhead. High boiling residues are removed from the bottom of the second column. 

Place 0-5 g. of the amino acid and 1 0 g. of phthalic anhdride in a Pyrex test-tube and immerse the lower part of the tube in an oil bath, which has previously been heated to 180-185°. Stir the mixture occasionally during the first 10 minutes and push down the phthalic anhydride which sublimes on the walls into the reaction mixture with a glass rod. Leave the mixture undisturbed for 5 minutes. After 15 minutes, remove the test-tube from the bath when the liquid mass solidifies, invert the test-tube and scrape out the excess of phthalic anhydride on the walls. RecrystaUise the residue from 10 per cent ethanol or from water. 

D. Methionine.—A suspension of 21.5 g. (0.063 mole) of this tricarboxylic acid in 350 cc. of hot water is heated on the steam bath and 40 cc. of concentrated hydrochloric acid (sp. gr. 1.19) is added. Carbon dioxide is immediately evolved and the substance goes into solution. After heating for one and a half hours, 200 cc. more of concentrated hydrochloric acid is added and heating is continued for forty-five minutes longer. The solution, on cooling, deposits phthalic acid this is filtered off and washed with two 50-cc. portions of water (Note 3). The combined filtrate and washings are evaporated to dryness on the steam bath under reduced pressure, and the dry residue is dissolved in... 

Phthalic anhydride [85-44-9] M 148.1, m 132°, b 295°. Distd under reduced pressure. Purified from the acid by extracting with hot CHCI3, filtering and evaporating. The residue was crystd from CHCI3, CCI4 or benzene, or sublimed. Fractionally crystd from its melt. Dried under vacuum at 100°. [Saltiel 7 Am Chem Soc 108 2674 1986.]... 

D. ci - -Thiabicyclo[4 .. Q]nonan S,S-Dioxide [Benzo[c]thiophene 2,2-dioxide, cis-octahydro-]. A solution of the sulfide (43.0 g., 0.303 mole) in 11. of ether is cooled to 0° and treated dropwise while magnetically stirred with 1.01. of 0.65iV ethereal monoperphthalic acid (0.65 mole). The mixture is kept overnight at 0°, after which time the precipitated phthalic acid is separated by filtration and the filtrate concentrated with a rotary evaporator. Bulb-to-bulb distillation of the residual oil at 0.05-0.1 mm. affords the sulfone as a eolorless liquid (48.5-50 g., 92-95%) (Note 11). This product is crystallized from ether-hexane to give a colorless solid, m.p. 39-41° (Note 12). 

This will lead initially to branched chain structures such as indicated schematically in Figure 2.10, G indicating a glycerol residue and P a phthalic acid residue. In due course these branched molecules will join up, leading to a cross-linked three-dimensional product. 

A solution of 10 g (0.023 mole) of cholesteryl acetate (mp 112-114°) in ether (50 ml) is mixed with a solution containing 8.4 g (0.046 mole) of monoperphthalic acid (Chapter 17, Section II) in 250 ml of ether. The solution is maintained at reflux for 6 hours, following which the solvent is removed by distillation (steam bath). The residue is dried under vacuum and digested with 250 ml of dry chloroform. Filtration of the mixture gives 6.7 g of phthalic acid (87% recovery). The solvent is evaporated from the filtrate under reduced pressure and the residue is crystallized from 30 ml of methanol, giving 6.0 g (58% yield) of -cholesteryl oxide acetate. Recrystallization affords the pure product, mp 111-112°. Concentration of the filtrate yields 1.55 g (15% yield) of a-cholesteryl oxide acetate which has a mp of 101-103° after crystallization from ethanol. 

Isocitral is left as a residue when reduced enolised citral is freed from isogeraniol by means of phthalic anhydride, and has the following characters —... 

The solvent was evaporated off under reduced pressure, and the residual gum refluxed with concentrated hydrochloric acid (50 g) for 6 hours. The solution was aliowed to cool overnight. It was filtered from the phthalic acid crystals, and freeze-dried, and to the pink residue was added acetone (160 g) and ethyl acetate (50 g). The mixture was left in the cold room overnight and the clear pink supernatant liquid poured off. The pink gummy hydrochloride remaining in the flask was dissolved in water (20 g), saturated sodium acetate solution added until precipitation was complete, and the product collected and dried in a desiccator. The crude p-bis-(2-chloroethyl)-aminophenylalanine (3.6 g) was crystallized from methanol giving colorless needles, MP 172° to 174°C (decomp.) of p-bis-(2-chloroethyl)-aminophenylalanine. 

The final residue from the mother liquor is an oil which does not solidify in a freezing mixture, and appears to be a mixture of p- and w-tolylcarbinols. Only a trace of phthalic acid (phenolphthalein test) was obtained by oxidizing this oil with permanganate the portion of it which was more readily soluble in water yielded a phenylurethan which depressed the melting point of the phenylurethan of either />-tolylcarbinol or benzyl alcohol. 

For fitting such a set of existing data, a much more reasonable approach has been used (P2). For the naphthalene oxidation system, major reactants and products are symbolized in Table III. In this table, letters in bold type represent species for which data were used in estimating the frequency factors and activation energies contained in the body of the table. Note that the rate equations have been reparameterized (Section III,B) to allow a better estimation of the two parameters. For the first entry of the table, then, a model involving only the first-order decomposition of naphthalene to phthalic anhydride and naphthoquinone was assumed. The parameter estimates obtained by a nonlinear-least-squares fit of these data, are seen to be relatively precise when compared to the standard errors of these estimates, s0. The residual mean square, using these best parameter estimates, is contained in the last column of the table. This quantity should estimate the variance of the experimental error if the model adequately fits the data (Section IV). The remainder of Table III, then, presents similar results for increasingly complex models, each of which entails several first-order decompositions. 

Soil/Plant. Degrades in soils and plants forming 1-naphthylamine and phthalic acid (Hartley and Kidd, 1987 Humburg et al., 1989). Residual activity in soil is limited to approximately 3 to 4 months (Hartley and Kidd, 1987). 

These data were measured at or extrapolated to ambient temperature and pH values. The data are discussed in the text. NA = not available. b/ Kq = soil water distribution coefficient (K ) divided by the organic carbon content of the soil, cj Whenever possible, half-life for soil dissipation is derived from the field data half-lives described in the text rather than lab data. As such, it may not represent a true first-order process. Value has been estimated from the equation in ref. 20. e/ Hydrolysis of total residues (aldicarb + sulfoxide + sulfone). pK for p -phthalic acid is 3.5. The chlorine atoms of DCPA should lower the pK to about 2. Conditions optimized for soil metabolism. 

Di(2-ethylhexyl) phthalate is available in a variety of technical grades (including a special grade for capacitor applications and a low residuals grade). Typical specifications are minimal ester content, 99.0-99.6% maximal moisture content, 0.1% and acidity (as acetic acid or phthalic acid), 0.007-0.01% (Aristech Chemical Corp., 1992 WHO, 1992). 

In the older method, still used in some CIS and East European tar refineries, the naphthalene oil is cooled to ambient temperatures in pans, the residual oil is separated from the crystals, and the cmde drained naphthalene is macerated and centrifuged. The so-called whizzed naphthalene crystallizes at ca 72—76°C. This product is subjected to 35 MPa (350 atm) at 60—70°C for several minutes in a mechanical press. The lower melting layers of the crystals are expressed as liquid, giving a product crystallizing at 78—78.5°C (95.5—96.5% pure). This grade, satisfactory for oxidation to phthalic anhydride, is referred to as hot-pressed or phthalic-grade naphthalene. 

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