P-substituted Derivatives Research Articles

Catalytic hydrogenation of C=N bond Communication 1. Study of hydrogenation of azomethines of benzylidene series

1. The hydrogenolysis of benzylideneaniline, and of its methyl and methoxy derivatives, in the presence of Pd/C proceeds selectively: the hydrogenolysis of the benzyl-N bond begins only after the absorption of the first mole of hydrogen. 2. Partial hydrolysis of the C=N double bond occurs under the hydrogenation conditions due to traces of water in the solvent. 3. The insertion of electron-donor substituants into the benzene ring, attached to the nitrogen, has little effect on the hydrogenation rate of the azomethine. The o-substituted azomethines hydrogenate somewhat faster than do the m- and p-substituted derivatives.

Anisotropy of the polarizability and steric structure of 1,2-diarylaziridines

1. A graphical method was proposed for the conformational analysis of aromatic compounds, based on a comparison of the molar Kerr constants of p-substituted aryl derivatives — the method of “isoconstant maps.” 2. A trans-configuration of aziridines — adducts of dichlorocarbene with certain benzylidine anilines — was established on the basis of the dipole moments. 3. Structures with C- and N-aryl substitution are noticeably distorted in comparison with the simplest analogs.

Synthetic inhibitors of glucocerebroside β-glucosidase

The glucocerebrosidase of human placenta was studied with various potential inhibitors. Several compounds that resemble the lipoidal product of enzyme action, ceramide, proved to be excellent inhibitors, acting by mixed modes (primarily noncompetitively). These were N-decyl- dl-erythro-3-phenyl-2-amino-l, 3-propanediol and several p-substituted derivatives. These compounds were also highly effective in rat spleen toward glucocerebroside and p-nitrophenyl β-glucoside as substrates. The compounds were inactive toward the analogous enzyme, galactocerebrosidase of rat brain, and were slightly stimulatory toward the rat brain enzyme which makes galactocerebroside. Longer and shorter N-alkyl groups proved to be less effective. Decanoic acid amides of phenylaminopropanediol and related compounds proved to be relatively inert, although some were stimulatory. Deoxycorticosterone β-glucoside was a moderately effective noncompetitive inhibitor and is apparently hydrolyzed by a different glucosidase. p-Nitrophenyl β-glucoside was also a moderately effective inhibitor, acting by mixed modes. p-Chloromercuribenzenesulfonate was a good inhibitor, presumably acting on a sensitive cysteine residue. It is concluded that cerebrosidase contains two sensitive sites, one catalytic and the other allosteric, each containing an important anionic group and able to bind glucosides and ceramide-like compounds.

Effects of N- and O-Acetylation on the UV-Absorption Spectra of m- and p-Substituted Derivatives of Aniline and Phenol

Experimental studies were carried out, n the shifts, f L bands, f and substituted aniline and phenols upon aeetylation. ln aniline derivatives, the shift (ay) was bathochromic when the substituent X is an electron donor, while the shift was hypsochromic when X is an acceptor. ln both cases, the shifts was found to increase linearly with an increase in eleetron donating or accepting character of X. The main factor affecting the direction of the shift was considered tobe an extent of electron transfer from the amino nitrogen atom towards the benzene ring the larger the contribution of this electron transfer to the L.-state is, the more the hypsochromic shift becbmes large. Thus, the hypsochromic shift isascribed to a decrease in electron releasing tendency of the amino nitrogen towards the benzene ring upon Nacetylation. The band displaced to the red side upon N-acetylation has the nature of the CT band of acetamide rather than the L.-bancl of aniline. The large bathochromic shift of acetamide band upon N-phenylation was assumed to be related to the electronic interaction between carbonyl and phenyl groups.In the cases of derivatives of phenol, the shifts could be accunted for only by the effect attributable to an increase in the apparent electronegativity of phenolic oxygen atom.

Polarographic study of the conduction of the polar effect of a substituent through the furan ring and side bridge groupings

The coefficients of conduction of the polar effect of a substituent through the furan ring and side bridge groupings were calculated by comparison of the polarographic half-wave potentials for the electroreduction of the nitro group in series of 5-substituted derivatives of 2-nitrofuran and p-substituted nitrobenzene derivatives by means of the ρ -ρ method. The polarographic method can be successfully used for this purpose in media in which the electrochemical process is not limited by the kinetics of the side process of surface protonation of the nitro group. It follows from the polarographic data and hyperfine structure of the ESR spectra of the anion radicals that the furan ring conducts the polar effect of substituents better (by a factor of 1.1–1.2) than the benzene ring. Depending on the electronic structure of the bridge groups, the introduction of bridge groups between the furan ring and the substituent decreases the conduction of the effect of substituents.

Mechanism of methemoglobin formation by diphenylsulfones: Effect of 4-Amino-4′-hydroxyaminodiphenylsulfone and other p-substituted derivatives

4,4′-Diaminodiphenylsulfone (DDS) can produce methemoglobinemia in vivo, apparently by the action of an unidentified metabolic product. To discern the chemical nature of such a compound, 13 p-substituted diphenylsulfones have been examined for their ability to oxidize hemoglobin (Hb) to methemoglobin (MHb) in human erythrocytes in vitro. 4-Amino-4′-hydroxyaminodiphenylsulfone (DDS-NOH) is most effective, 1·9 × 10 −5 M of drug oxidizing as much as 60 per cent of the Hb, or 100 heme equivalents/mole of DDS-NOH in 2 hr. Oxygen is required for this process, and glucose, while not required, enhances MHb formation. With dialyzed hemolysates and solutions of purified Hb, the heme equivalents oxidized/mole of drug becomes less than 10, but a ratio of 80 : 100 can be restored by adding reduced glutathione (GSH) or NADPH. Apparently DDS-NOH produces MHb by coupled oxidation with Hb and O 2 and DDS-NOH can be regenerated by reducing compounds to yield the high heme oxidation ratio. In intact cells, DDS-NOH causes a 7-fold increase in the activity of the hexose monophosphate shunt as measured by 14CO 2 production from glucose 1- 14C. Incubation with galactose, which is minimally oxidized by the shunt pathway, results in decreased formation of MHb, and the GSH concentration drops by 75 per cent. Depletion of intracellular GSH by a sulfhydryl oxidizing compound also reduces MHb formation by DDS-NOH. These observations implicate GSH or NADPH or both in the recycling of DDS-NOH in erythrocytes. Consistent with these interpretations, DDS-NOH produced only one-half as much MHb in erythrocytes from three individuals with glucose 6-phosphate dehydrogenase deficiency as it did in normal erythrocytes.

Structures of Three Isomeric Dimers of 2,4,5-Triphenylimidazolyl

Abstract In addition of the piezochromic and the photochromic (dimer A) dimers of 2,4,5-triphenylimidazolyl, two new isomeric dimers were prepared; one (dimer B) being photochromic and the other (dimer C) non-photochromic. Several p-substituted derivatives of the dimers were also prepared. By comparison of their NMR and IR spectra, structures (a), (b), and (c) were assigned to the dimers A, B, and C, respectively. On treatment with hydrochloric acid in ethanol, dimer A underwent heterolytic cleavage and gave a mixture of 2-ethoxy-2H- and 4-ethoxy-4H-2,4,5-triphenylisoimidazole, and 2,4,5-triphenylimidazole.

Studies in the imidazole series

A new synthesis of derivatives of imidazo[2,1-b]thiazole from 2-halogenoimidazoles has been effected. The reaction of 2-bromo-4,5-diphenylimidazoles with phenacyl bromide and its p-substituted derivatives has given the corresponding 2-bromo-1-phenylimidazoles, by the heating of which with thiourea and subsequent cyclization of the resulting 2-mercapto-1-phenacylimidazoles under the action of phosphorus oxychloride a number of 2,5,6-triarylimidazo[2,1-b]thiazoles has been synthesized.

Pyrimidine reactions. XX. Thermal rearrangement of 5-(p-substituted phenyl)-2(and 4)-methoxypyrimidines.

2(and 4)-Methoxy-5-phenylpyrimidine and some p-substituted derivatives are rearranged by heating in triethylamine to give the corresponding N-methyl-2(or 4)-oxopyrimidines. The log k1 values for rearrangement of the 2-methoxypyrimidines show a rectilinear relationship to the known σ values for p-substituted phenyl groups, save when such values are highly negative. 4-Methoxy-5-phenylpyrimidine and its p-nitro-derivative rearrange more rapidly than their respective 2-methoxy-isomers; in addition, each gives a mixture of N-1 and N-3 methylated products in which the latter predominates. These facts are consistent with the recently proposed intermolecular and ionic nature of such rearrangements. Some of the intermediate 2-hydroxy-5-phenylpyrimidines and their N-methyl derivatives are made by a novel modification of the principal pyrimidine synthesis, namely condensation of urea or N-methylurea with 3-imino-2-phenylpropionaldehyde or a derivative. 1H N.m.r. and u.v. spectra are used to follow rearrangements and to confirm structures.

Studies on dehydro-L-ascorbic acid arylosazones. Part II. Conversion into substituted azo-pyrazolones

N.m.r. and i.r. spectroscopy, acetylation, benzoylation, and oxidation with periodate confirmed that the rearrangement product of dehydro-L-ascorbic acid phenylosazone is 1-phenyl-4-phenylazo-3-(L-threo-1,2,3-trihydroxypropyl)pyrazolin-5-one. A number of p-substituted derivatives of this compound and their acylation products have also been prepared.

Organic Sulfur Compounds. IX. The Reactions of N-Sulfinylamines with Nitrogen Tetroxide and Nitrosyl Chloride

Abstract N-Sulfinylaniline reacted with nitrogen tetroxide to form the anhydrous benzenediazonium nitrate. The reactions of N-sulfinylaniline and several of its p-substituted derivatives with nitrosyl chloride also gave the anhydrous diazonium chlorides in the crystalline state. Aliphatic N-sulfinyl-amines reacted with nitrosyl chloride to form alkyl chlorides, probably by the decomposition of the initially-formed diazonium chlorides; during this reaction, no rearrangement of the alkyl group was observed.

Mobilità molecolare e fenomeni di rilassamento meccanico in alcuni polivinilbenzoati

The elastic and inelastic behaviour of polyvinyl benzoate and some of its monosubstituted derivatives in the temperature range between 77 and 400°K has been studied by an electrostatic method at medium frequency. In polyvinyl benzoate and its p-substituted derivatives the presence of a relaxation phenomenon at temperatures between 85 and 120°K and of a relaxation phenomenon at temperatures between 230 and 250°K was found. The position on the temperature scale and the height of the dissipation maxima corresponding to such phenomena are influenced by the nature of the substituting groups. Ortho and meta-substituted compounds do not show mechanical relaxation effects at the lower temperatures, while in these the phenomenon gives way to a shoulder of the Q 1−- T curves together with a variation of the slope of the ν- T curves in a temperature interval between 220 and 300°K. The observed phenomena are correlated with the movement of benzene nuclei and all the lateral groups present in the macromolecules of the examined compounds. The effect of the nature and position of the substituents present on the relaxation phenomena is discussed. The approximate values of the transition temperature into the vitreous state for the compounds examined have also been determined.

Oxidation of Alcohols with t-Butyl Chromate. II. The Oxidation of Primary Aromatic Alcohols

Abstract The oxidation with t-butyl chromate has been carried out with benzyl alcohol, its p-substituted derivatives and trans-cinnamyl alcohol, and also with β-phenylethyl alcohol. In the former alcohols, the corresponding aldehyde was obtained as the main product, but the corresponding ester was not formed. On the other hand, the latter alcohol, containing a methylene group adjacent to the hydroxymethyl group, produced the corresponding ester, aldehyde and acid, as in the case of a saturated primary aliphatic alcohol.

Paper chromatography of p-substituted derivatives of 1-aryl-3,3-dimethyltriazene

Paper chromatography of p-substituted derivatives of 1-aryl-3,3-dimethyltriazene

Infrared Spectra of Benzamide, its p-Substituted Derivatives, Pyridinecarboxylic Acid Amides and Pyrazinamide.

Infrared absorption spectra of benzamide, p-substituted benzamide, pyridinecarboxylic acid amides, pyrazinamide and their homologs were measured in Nujol mull and in solution, and the assignment of the characteristic absorption has been made. The infrared absorption spectral data suggested the crystal structure of isonicotinamide, α-and β-type of pyrazinamide and β-type of pyrazinamide. 1) Benzamide, p-substituted benzamides, picolinamide (β-type), and pyrazinamide (β-type) showed a similar absorption tendency and are therefore supposed to have a similar crystal structure. β-Type of picolinamide and pyrazinamide is different in symmetric center. 2) Nicotinamide and isonicotinamide showed the same absorption tendency and, therefore, the same crystal structure was formed. 3) Pyrazinamide (α-type) and picolinamide (α-type) showed the same absorption tendency and is supposed to form the same crystal structure.

安息香酸およびその核置換誘導体ならびに水の存在下での過酸化ラウロイルとジメチルアニリンとの反応

安息香酸およびその核置換誘導体ならびに水の存在下での過酸化ラウロイルとジメチルアニリンとの反応

Studies on Hydroperoxides. I-III. I. Acid-catalysed Oxidation of p-Bis(I-hydroxyisopropyl) benzene, Dimethylphenylcarbinol and its p-Substituted Derivatives with Hydrogen Peroxide

p-ビス (1-オキシイソプロピル) ベンゼン, ジメチルフェニルカルビノールおよびその p-置換体 (-OCH3, -H3, -Br) はいずれも酸触媒の存在下, 30% の過酸化水素と反応し, 相当するヒドロペルオキシドを生成した。さらにこれらのヒドロペルオキシドは酢酸溶媒中で酸分解を起こし, 好収率でフェノール誘導体が得られた。これらのフェノール誘導体はヒドロペルオキシドの酸分解によって生ずるフェノニウムイオンをすべて生成するものと思われる。

Metal Chelates of Tetraphenylporphine and of Some p-Substituted Derivatives1,2

Metal Chelates of Tetraphenylporphine and of Some p-Substituted Derivatives^1,2

The General Applicability of a Fixed Scale of Inductive Effects. II. Inductive Effects of Dipolar Substituents in the Reactivities of m- and p-Substituted Derivatives of Benzene1,2

The General Applicability of a Fixed Scale of Inductive Effects. II. Inductive Effects of Dipolar Substituents in the Reactivities of m- and p-Substituted Derivatives of Benzene^1,2