1. Carbobenzoxy-O-benzylseryltyrosyl-O-benzylserylmethionine methyl ester, which has the N-terminal tetrapeptide sequence of corticotropin and α-MSH, has been synthesized. 2. It has been shown that the O-benzylseryl peptide bond is very stable to an alkali treatment. 3. Syntheses of the relating serine peptide derivatives have been described.
It was found that the semi-empirical method proposed by Pariser and Parr can be applied to the n–π* transition as well as the π–π* transition in acrolein. In acrolein the (n, π*) triplet state is the lowest state. A weak band in the red side of the 0–0 band is a hot band and it is not the n–π* singlet-triplet transition band. The n–π* triplet band anticipated from calculation could not be found.
The sirup obtained as a by-product with β-1-C-phenyl-2-acetamido-2-deoxy-3,4,6-tri-O-acetyl-D-glucopyranoside by the action of phenylmagnesium bromide on acetobromo-D-glucosamine hydrobromide has been deacetylated and chromatographed to yield the α-anomer. Several α-derivatives have been described, among which, α-1-C-(p-nitrophenyl)-2-dichloroacetamido-2-deoxy-D-glucopyranoside which is a chloramphenicol derivative showed no antibiotic activities. The application of Hudson’s rules of isorotation to the anomeric compounds in this series is discussed.
Vapor phase catalytic dehydrogenation of 1,4-butanediol to γ-butyrolactone with reduced copper supported on various carriers was studied. It was found that copper supported on zinc oxide or magnesium oxide was a superior catalyst. In the case of a catalyst consisting of 20% copper and 80% zinc oxide, the yield and space time yield of γ-butyrolactone were 95% and 0.28 at 230∼240°C, respectively.
The polyaddition reaction of diphenylsilane to diallyl phthalate was studied. The reaction was found to be of the second order at the initial stage. The over-all rate is proportional to the initial monomer and catalyst concentration. The over-all activation energy calculated for this reaction was found to be 12kcal./ mol. at 80∼120°C. By a similar method following polyesters have been prepared from diphenylsilane and diallyl carboxylates: Polydiphenylsilylene 3, 3′-bis(trimethylene)oxalate, malonate, succinate, adipate, sebacate, phthalate, isophthalate and terephthalate. Their molecular weight and inherent viscosity were determined and properties have been described.
The red solution prepared by adding sodium hydroxide to an aqueous picryl chloride solution containing a small quantity of ethanol, was relatively stable even at room temperature. The red solution showing the two bands at about 416 and 490 mμ, changed into the yellow solution showing the band similar to that of picric acid under the same condition. Accordingly, the 416 and 490 mμ bands may be due to the intermediate of Meisenheimer’s type in the process of the substitution reaction of picryl chloride to picric acid. In the presence of sodium hydroxide, picryl chloride in ethanol as well as in acetone finally gave the absorption bands analogous to that of picric acid in water containing ethanol. The red solutions in ethanol and in acetone, therefore, would be due to the same intermediate.
Polymerization of acenaphthylene was studied kinetically in heptane or toluene in the presence of titanium butanate-aluminum triethyl or titanium butanate-lithium aluminum hydride at 40∼95°C. Activation energy was computed as 14.3 and about 13kcal./mol. Molecular weight of the polymer obtained was 125000, while [η]Benzene30° was only 0.035 (c=g./ 100ml.).
1) The colloidal characteristics of the mucilage from “Tororo-aoi” such as the elasticity, spinnability, and so on are caused by the network built by interlocking between short branched chains of the mucin molecules, fibrous glucosans and proteins. 2) The remarkable change of the colloidal nature by heating is caused by breaking down the interlocking by oxidation.
1. Like aliphatic dinitriles, polyamide having benzene nucleus and -CONH- linkages was synthesized by condensation polymerization reaction of aromatic dinitriles and formaldehyde in concentrated sulfuric acid. 2. The condensation polymer obtained from terephthalonitrile had the greatest intrinsic viscosity among ortho-, iso-, tere-phthalonitrile and p-xylylene cyanide. A product of the highest condensation polymerization degree was obtained, by adding the 1.025: 1 molar mixture of paraformaldehyde and terephthalonitrile in small portions into ten molar amounts of 95% sulfuric acid at 0°C and then stirring for ten hours at the same temperature. 3. These condensation polymers were insoluble in almost all organic solvents and had no melting and softening point. They decomposed above 300°C.
In aqueous solutions uracil exists predominantly in the diketo form, whereas in alkaline solutions it exists as an approximately 1:1 mixture of two deprotonated forms. The two deprotonated anions show ultraviolet absorptions similar to the anions of 1-methyluracil and 3-methyluracil, and the main contributing canonical structures which give rise to the general absorption feature of the anions are discussed. The peak shifts accompanying N-alkylation or deprotonation may be summarized in a simple empirical rule. Individual ionization constants have also been estimated. The results of uracil can be extended to thymine, uridine, thymidine, and their phosphates. The pesent method can probably be extended to other systems containing two dissociable protons.
The secondary electron emission from the non-activated and activated surfaces of copperberyllium (4%) by the impacts of various noble gas and hydrocarbon ions was studied together with the determination of the surface structure by the electron diffraction analysis. The main results obtained are as follows. (1) The considerably thick layer of beryllium oxide is formed in the neighborhood of the target surface activated by oxygen at the temperature range of 350 to 480°C. (2) The oxide films of copper are formed on the target surface by electropolishing, but these oxides easily undergo reduction by the prolonged ion bombardments. (3) The optimum temperature of activation for the electron yield seems to be about 420°C, and the electron yield for the activated target surface treated at 350 or 420°C is only slightly dependent upon the ion kinetic energy. (4) No measurable decrease in the electron yield for the activated surface treated at 420°C was obtained by the prolonged bombardments of various positive ions for ten hours, while the electron yield for the non-activated surface decrease about 20 per cent by the prolonged bombardments of ions for five hours. (5) Under the present experimental conditions, the mechanism of the electron ejection process seems to be considerably complicated and it is difficult to deduce any definite conclusion for the electron ejection process.
1) 3-Acetamido-3-deoxy-2,4,6-tri-O-methyl-D-glucose (I) and N-2,4-dinitrophenyl) derivative (II) of 6-amino-6-deoxy-2,3,4-tri-O-methyl-D-glucose have been isolated from the hydrolyzate of exhaustively methylated N-acetyl kanamycin. 2) II has been synthesized from 6-amino-6-deoxy-3,5-benzylidene -1,2-isopropylidene-D-glucose.
Procedures have been developed for the spectrophotometric determination of trace amounts of beryllium, copper and iron(III) with sodium-2″,6″-dichloro-4′-hydroxy-3,3′-dimethylfuchsone-5,5′-dicarboxylate. Certain ions that interfere with the beryllium determination are removed by an oxine precipitation. Ions that interfere with the analysis of copper and iron(III) are removed with an anion exchange resin column. Accuracy and precision are good. Beer’s law is obeyed up to about 0.3 p.p.m. of beryllium, about 4 p.p.m. of copper and about 3 p.p.m. of iron.
The electronic spectra of monosubstituted benzenes are examined from the viewpoint of semi-empirical MO theory. To allow for electronic interaction, the simple LCAO method is refined in the light of purely theoretical procedure, configuration interaction being included. The refined method is particularly convenient for dealing with the spectra of substituted organic compounds. The origins of the absorption bands for phenol and aniline are clarified on the basis of the calculated excitation energies, oscillator strengths and changes of charge distribution accompanying electronic transitions. The nature of the second excited state of aniline is discussed in detail, in connection with the problem of electron transfer.
The ultraviolet absorption spectra of α-, β-naphthols and α-, β-naphthylamines have been newly measured down to 200 mμ. On the basis of a calculation which was carried out in the same manner as in the preceding paper, the effect of substitutions at α- and β-positions upon the spectrum of napthalene has been explained and the assignment of the observed absorption bands has been made. It is suggested that, upon substitution at the α-position, the Au→B3u+ band of naphthalene splits into two electronic bands because of the interaction of the B3u+ state with a B1g+ state. Molecular diagrams are given for naphthylamines and for aniline.
The curves of dx/dt against t were obtained with accuracy; in consequence, the complication of the curves appeared, and the complication may be associated with the irregularities of the bubbling and splashing.
Infrared spectra of tropolone, 4-isopropyltropolone and 3-bromotropolone in the solid, liquid and solution in carbon tetrachloride were measured with a calcium fluoride prism in the region of 3600∼2600 cm−1. The absorptions of O-H stretching vibration in these compounds in dilute solution are strongest at around 3120 cm−1 with numerous branches, and these bands shift gradually to the higher wave number side with 100∼88 cm−1, as the concentration increases and the compound transits to the liquid or solid state. This character was explained by the assumption that the tropolone skeleton has a stable chelate system and that the intermolecular action increases with the increase of concentration. In the solid state, a distinct band corresponding to the O–H group of Ib type was also observed at around 3540 cm−1.
In order to find infrared absorption of tropolone, especially the absorption that can be assigned to the C–O–H group, the spectrum of 2-deuteroxytropone was measured and there were discussions chiefly on absorptions in the finger-print region. The absorption bands at around 3150, 1490, 1267 and 726 cm−1 were assigned to the vibration of C–O–H group. In this connection, some mention was made on deuterated tropolone and considerations were made on the assignment of vibrational spectra of tropolone, as summarized in Table II.
Rates of solvolysis of cis- and trans-1,2- and-1,4-di-p-toluenesulfoxycyclohexanes were measured at 99.8°C in methanol or in acetic acid. In all cases, the solvolysis was approximately of first order. Mean rate constants of the solvolysis increased in going from acetic acid to alcohol, and were enhanced by the addition of a small amount of alkali, in agreement with the behavior in solvolysis of primary alkyl tosylates. The 1,2-isomers were not solvolyzed in acetic acid in 20 hr., and in ethanol containing EtONa in 0.02 mol./1., the ratio of kcis to ktrans was 5.6. In the case of the 1,4-isomers, the ratio was ca. 0.5 in acetic acid, 0.9 in methanol without alkali, 1.1 in methanol with MeONa in 0.013 mol./1. and 1.6 in methanol with MeONa in 0.02 mol./1.
The phase relationship in the system 3CaO·P2O5–MgO–SiO2 was investigated by a cooling experiment in the usual manner. The system 3CaO·P2O5–MgO, a side of this triangle, is a simple binary one, its eutectic being located at the composition of 4∼7% by weight of magnesia and 1570±20°C. The system 3CaO·P2O5–2MgO·SiO2 is not binary over the temperature of about 1350°C, below which it is considered as binary. Above 1350°C, nagelschmidtite is formed over the whole composition range and crystallized primarily from liquid at a high 3CaO·P2O5 portion. The minimum liquidus temperature is 1394°C, which is located at the composition of 70% C3P and 30% M2S. The system 3CaO·P2O5–MgO–2MgO·SiO2 was considered to be complex owing to the presence of nagelschmidtite, but the eutectic among their three components is located at the composition of 70% 3CaO·P2O5, 21% MgO, and 9% SiO2, and 1362±5°C. From the results described above and from those of the author’s previous reports, the preliminary phase diagram of the system 3CaO·P2O5–MgO–SiO2 was constructed. In this diagram the problem that nagelschmidtite is formed in the composition range which is rich in 3CaO·P2O5 was not mentioned in detail. In addition to this, it was found by X-ray examination that β-tricalcium phosphate may be apparently stabilized at a higher temperature than β-α transition point, and has the appearance of dissolving magnesia component.
The spectral changes of Congo Red solution with the addition of Tween 80 and cetyl pyridinium chloride were measured at various pH. The wavelength of the absorption peak of the interaction product between Congo Red and Tween 80 is 510 mμ in the acidic medium as well as those in the neutral and the basic ones, from which it is considered that they produce a molecular compound of a definite constitution irrespective of the medium pH. However, since the amount of Tween 80 required to show the same effect in spectra increases with lowering pH, it is considered that only a base form of Congo Red is probably active and binds with Tween 80 at the amino groups. The solutions of Congo Red containing sufficient cetyl pyridinium chloride have an absorption peak at 460 mμ. The product is completely precipitated as the ratio of Congo Red to cetyl pyridinium chloride is 1/2 and dispersed in both sides of this ratio, which depends little on the medium pH. This is considered to show that cetyl pyridinium chloride binds with Congo Red at the sulfonate groups, the product becomes most hydrophobic as two sulfonates in a molecule are blocked and hydrophilic with an excess of the detergent.