Solubilities of the systems acetanilide-water-acetic acid, phenacetin-water-acetic acid, and p-acetanisidine-water-acetic acid were measured at 10°, 30°, and 50°. In general, the solubility of acetamino compounds tended to increase with the increasing concentration of acetic acid and higher the temperature. The solubility of acetamino compounds at various temperatures, i.e. the saturation curve, reached the maximum at around 5% concentration of water and the solubility tended to decrease with the decreasing amount of water. The solubility of acetamino compounds was also found to decrease with the increase of their molecular weight.

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2-Methyl-4-amino-6-hydroxypyrimidine (I) submits to the Mannich reaction in acid medium with formaldehyde and piperidine, dimethylamine, or dethylamine and forms 5-piperidinomethyl (IIa), 5-dimethylaminomethyl (IIb), or 5-diethyl-aminomethyl (IIc) compound. (I) also submits to the Mannich reaction even with formaldehyde and methylamine to form the 5-methylaminomethyl derivative (IId) though the yield is poor compared to the use of secondary amines. 2-Methyl-4, 6-dihydroxypyrimidine (VI) also forms the 5-piperidinomethyl derivative (VII) by reaction with formaldehyde and piperidine but the yield is also poor in this case. 2-Methyl-4-amino-5-aminomethylpyrimidine (VIII) was obtained by heating the methiodide of 2-methyl-4-amino-5-dimethylaminomethylpyrimidine (Vb), derived from (IIb), in conc. ammonia water.

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2-Methyl-4-amino-6-hydroxypyrimidine (I) undergoes Mannich reaction with formaldehyde and piperidine, even in aqueous alkali solution and forms 2-methyl-4-amino-5-piperidinomethyl-6-hydroxypyrimidine (II), but the use of an excess of formaldehyde and piperidine results in the formation of the bis (piperidinomethyl) compound (III) of (I). Examination of the chemical properties and ultraviolet absorption spectrum of the bis compound (III) indicated the compound to be 2-methyl-4-piperidinomethylamino-5-piperidinomethyl-1, 6-dihydropyrimid-6-one (IIIf) and, at the same time, (I) and (II) were assumed to be the 1, 6-dihydropyrimid-6-one compounds (Ia) and (II′). 2-Methyl-4-methylamino-1, 6-dihydropyrimid-6-one (VII), similar to the 4-amino compound (Ia), also undergoes Mannich reaction with formaldehyde and piperidine to form 2-methyl-4-methylamino-5-piperidinomethyl-1, 6-dihydropyrimid-6-one (VIII).

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Infrared absorption spectral analyses of the pyrimidine derivatives reported in the preceding paper revealed the following facts. The 4-aminopyrimidine derivatives without a piperidinomethyl group in the 5-position shows a normal absorption of the primary amine in a carbon tetrachloride solution, while the absorption of the primary amine of the 4-amino group in the 4-amino-5-piperi-dinomethyl derivative, in carbon tetrachloride solution, shifts to a longer wave length region by the intramolecular hydrogen bonding. The absorption spectrum has endorsed the structure of the bis (piperidinomethyl) compound of 2-methyl-4-amino-6-hydroxypyrimidine, which had been assumed as 2-methyl-4-piperidino-methylamino-5-piperidinomethyl-6-hydroxypyrimidine. The absorption band of OH at 3000-2700cm^-1 in 6-hydroxypyrimidine derivatives was observed at 2200-2100cm^-1 by deuterium substitution from which it was assumed that the compound is present as a dimer, indicated in Fig. 5 (a).

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The crude flavonoid glycosides obtained from Cyrtomium falcatum Presl and C. Fortunei J. Sm., and its variety, var, clivicola Tagawa, were hydrolysed, respectively yielding two new flavanones, cyrtominetin (I) and cyrtopterinetin (II), besides kaempferol and quercetin. The analytical values of (I) agree with the formula C₁₇H₁₆O₆ and (I) forms a tetraacetate, while (II) gives a triacetate and its analytical values agree with C₁₇H₁₆O₅. (I), (II), and their acetates show weak optical rotatory power and do not possess any methoxyl group.

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Flavonoid glucosides were isolated from Cyrtomium falcatum Presl, C. Fortunei J. Sm., and its variety, var. clivicola Tagawa, by the use of chromatopile or paper partition chromatography and two new glucosides, cyrtomin and cyrtopterin, which are monoglucoside of cyrtominetin and cyrtopterinetin, respectively, were obtained besides astragalin and isoquercitrin. The flavonoids in Cyrtomium Yarnamotoi Tagawa, C. tsukusicola Tagawa, C. caryotideum Presl, and C. macrophyllum Tagawa were examined with a small amount of each material by paper partition chromatography and the results obtained are listed in Table IV.

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Near-ultraviolet absorption spectra were measured of 19 compounds of resacetophenone and nitroresorcinol series in acid, neutral, and alkaline solvents. Resacetophenone series compounds were found to exhibit four absorption bands between 205 and 350 mμ, at 210-220, about 230, 270-280, and 315-330 mμ. Their spectral analysis revealed that the bands at about 230 and 315-330mμ corresponded to the two bands of o-hydroxyacetophenone, and those at 210-220 and 270-280mμ to those of p-hydroxyacetophenone. Therefore, the two bands in the longer wave length region belong to the K-band and those in the shorter region to the B-band. Relationship between the facility or difficulty of methylation of the two hydroxyls in these compounds with dimethyl sulfate and their spectra was discussed. Ultraviolet absorption maxima of the compounds which can or cannot form chelation in neutral and acid medium were compared and it was found that in both solvents, there were a difference of around 7mμ in the band at 270-280mμ and around 10mμ in the band at 315-330 between these compounds.

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Absorption spectra were measured of 12 kinds of compounds, including 4-phenylazoresorcinol, 4-(o-tolyl) azoresorcinol, 4-nitrobenzeneazoresorcinol, and the mono-and dimethyl ethers in acid, neutral, and alkaline solvents. Absorption of 4-nitrobenzeneazoresorcinol series compounds were observed only in the visible region, but the compounds of other two systems were observed up to the ultraviolet range, and the absorption maxima of the B- and K-bands were determined. The absorption maxima of these compounds were found to vary greatly according to the reaction of the solvent, shift to the longer wave length region being most marked in alkaline side. The displacement of the absorption maxima in compounds with free hydroxyl and its methylated derivatives were compared in acid and neutral medium to examine its relationship with chelation. The absorption maxima in acid solvent was found to have shifted by 10-15mμ (at 370-380mμ) due to chelation while this point remained obscure in a neutral medium. Discussions are also made on the structure of 4-nitrobenzeneazoresorcinol.

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Alkyl α-phenyl-γ-tert-aminocrotonates were synthesized as having the characteristic structures of the known synthetic analgesics, 4-phenyl-4-ethoxycarbonyl-N-methylpiperidine and 1, 1-di(2′-thienyl)-3-dimethylaminobut-1-ene. Pharmacological tests revealed that (III) possessed the strongest action though it seemed to be much weaker than that of morphine.

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For the analgesic effect of analgesics, Prof. Ogyu forwarded a theory that there is a close relationship between the adrenergic and anticholinergic activities. Attempts were made to find two kinds of drugs each having such activities but not possessing any habituation tendencies in order to obtain a new analgesic without the fear of habituation. As a compound having such anticholinergic activity, fatty acid esters with N-methylpiperazino or morpholino groups in α-position were prepared.

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An identification reaction for pyrazinamide using p-dimethylaminobenzaldehyde or sodium pentacyanoammineferroate was discovered. Further, coloriretric determination of pyrazinamide was carried out by the utilization of the bright red coloration exhibited by the reaction of pyrazinamide with sodium nitroprusside in sodium carbonate alkalinity. The determination is carried out after removal of pyrazinoic acid, if such is present, through anion exchange resin.

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The four isomers of kainic acid, i. e. α- (α-I), β- (β-I), α-allo- (α-allo-I), and β-allo- (β-allo-I) kainic acids, are decomposed by ozonic oxidation and form corresponding methyl ketone compounds, α-methyl (α-III), β-methyl (β-III), α-allomethyl (α-allo-III), and β-allomethyl (β-allo-III) ketone compounds. The relationship between these and the methyl ketone compounds obtained to date was clarified.

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Examination of the mutual relationship between the four methyl ketone compounds reported in the preceding paper revealed that the α-methyl ketone compound (α-III) underwent facile isomerization to α-allomethyl ketone compound (α-allo-III) and that the β-methyl ketone compound (β-III) similarly underwent isomerization to β-allomethyl ketone compound (β-allo-III). It was found that (α-allo-III) can be derived to (β-allo-III) by the kainic inversion and vice versa by retrokainic inversion. These facts show that these four methyl ketone compounds are all steric isomers.

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Ozonolysis of N-acetyl-α-kainic acid (α-II) afforded N-acetyl-α-methyl ketone compound (α-IV) which was also derived from α-methyl ketone compound (α-III) by acetylation. On the other hand, ozonolysis of N-acetyl-α-allokainic acid (α-allo-III) gave N-acetyl-α-allomethyl ketone compound (α-allo-IV) which was also derived from α-allomethyl ketone compound (α-alto-III) by acetylation. Heating of (α-IV) with mineral acids or water resulted in concurrent isomerization and hydrolysis to form (α-allo-III), which was also obtained on the hydrolysis of (α-allo-IV). (α-IV) underwent isomerization to (α-alto-IV) when heated with glacial acetic acid.

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Catalytic reduction of α-methyl (α-III) and α-allomethyl (α-allo-III) ketone compounds, each in aqueous solution, respectively yielded the lactone of α-hydroxyethyl compound (α-VI) and α-allohydroxyethyl compound (α-allo-V). The same results were obtained by the catalytic reduction of (α-allo-III) in acetic acid solution. Catalytic reduction of (α-allo-III) in dilute hydrochloric acid or lactonization of (α-allo-V) in conc. sulfuric acid gave the lactone (α-allo-VI) which immediately underwent fission of the ring by neutralization to form (α-allo-V), making it impossible to isolate the lactone. It was thereby found there were a marked differences in the ease or difficulty of lactonization and stability of the lactones formed in the reduction of (α-III) and (α-allo-III).

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Summarizing the experimental results reported in Parts XXXI to XXXIV of this series, the steric configuration of the four diastereoisomers of the methyl ketone compounds (III) was assumed as follows.
1) Configuration of C₂-From the specific optical rotation curve based on Lutz's law, C₂ in (α-III) and (α-allo-III) are in L-system and those of (β-III) and (β-allo-III) in D-system.
2) Steric configuration of carboxyl in C₂ and acetic acid in C₃-Since the kainic and retrokainic inversion occur between (α-allo-III) and (β-allo-III), and from other experimental results, those in (α-III) and (α-allo-III) are in cis-configuration and those in (β-III) and (β-allo-III) are in trans.
3) Configuration of acetic acid in C₃ and acetyl in C₄-From the facts of isomerization of (α-III) and (β-III) respectively to (α-allo-III) and (β-allo-III), and of the facile formation of a stable lactone (α-VI) by the catalytic reduction of (α-III) as against the formation of a by droxyethyl compound (α-allo-V) from (α-allo-III), the lactone (α-allo-VI) being extremely labile, those in (α-III) are in cis and those in (α-allo-III) are in trans.
Based on these assumptions, the steric structures for these four compounds were proposed as shown in Fig. 2 and in Table I.

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Treatment of α-kainic acid (α-I) and α-allokainic acid (α-alto-I) with conc. sulfuric acid, under the same conditions, affords a stable α-kainic acid lactone (α-VII) from (α-I) but a labile α-allokainic acid lactone (α-allo-VII) from (α-allo-I), which easily undergoes hydrolysis in aqueous solution to change to α-allohydroxy acid (α-allo-VIII). These results suggest that (α-VII) is a stable cis-lactone compound and (α-alto-VII) the labile trans-lactone compound. It follows, therefore, that the isopropenyl and acetic acid groups in kainic acid and its stereoisomers are cis in α- and β-series, and trans in α-allo- and β-allo-series. Summarizing the results herein obtained and the steric configuration of the α-carbon atom and the relationship between the carboxyl and acetic acid groups as reported in Part XXVI of this series, it seems that these steric structures are more correctly represented by those shown in Fig, 4 and Table I in the present paper, rather than those proposed in Part XXVII.

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Treatment of kainic acid with hydrochloric acid or bromine water yields kainlc acid lactone or bromokainic acid lactone but the same treatment of α-allokainic acid does not afford the lactone and non-lactonized hydroxy acid alone is obtained. These experimental results also suggest the appropriateness of determining the configuration of the carboxymethyl and isopropenyl groups in kainlc acid as in cis, and those in α-allokainic acid as in trans, which can rationally explain various reactions listed in Table I.

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By the reaction of 2-(2-mercapto-4-methyl-5-thiazolyl) ethanol (I) or ethyl 2-mercapto-4-methyl-5-thiazolylcarboxylate (VIII) and 2-(2-chloro-4-methyl-5-thiazolyl) ethanol (IV) or ethyl 2-chloro-4-methyl-5-thiazolylcarboxylate (IX), the corresponding bis (4-methyl-5-β-hydroxyethylthiazoiyl-2) sulfide (V), bis (4-methyl-5-ethoxycarbonylthiazolyl-2) sulfide (X), and 4, 4′-dimethyl-5-β-hydroxyethyl-5′-ethoxycarbonyldithiazolyl-2, 2′ sulfide (XII) were obtained. However, in the reaction of (I) and (IX), and of (IV) and (VIII), (V) and (X) were obtained as by-products besides (XII).

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Three kinds of oxazole-carboxylic acids were prepared. Cyclization of ethoxalyl-aminoacetophenone (I) with phosphoryl chloride in benzene afforded ethyl 5-phenyloxazole-2-carboxylate (II) as plates, m.p. 60-61°, in 70% yield. 2-Carboxylic acid (III) came as white crystalline powder, m.p. 80-82° (decomp.); hydrazide (IV), pale yellow needles, m.p. 164°. Cyclization of ethyl α-acetaminoacetoacetate (V) with phosphoryl chloride in benzene afforded ethyl 2, 5-dimethyloxazole-4-carboxylate (VI) as colorless oil, b.p₁₁ 117°, in 70% yield; hydrazide, pale yellow needles, m.p. 114-116°. Heating of ethyl α-chloroacetoacetate and benzamide, followed by hydrolysis, afforded 4-methyl-2-phenyloxazole-5-carboxylic acid as colorless needles, m.p. 237° (decomp.), yield, 2.4%.

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By heating ethyl α-acetoxyacetoacetate (I) and RCONH₂, the corresponding 2-R-4-methyloxazole-5-carboxylic acids (III) were obtained; R=H, m. p. 238° (decomp.), R=CH₃, m. p. 247° (decomp.), R=C₆H₅, m. p. 237° (decomp.), R=C₆H₅CH₂, m. p. 238° (decomp.). In these reactions, 2, 4-dimethyloxazole-5-carboxylic acid (V) was invariably obtained as a by-product in each case. It was found that the presence of barium carbonate increased the amount of the carboxylic acid formed.

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It was shown in the previous paper that α-trans-π-dihalo-d-camphor underwent peculiar isomerization by fuming sulfuric acid and formed 6-trans-π-dihalo-l-camphor. From the assumption of the racemization mechanism of camphor by sulfuric acid forwarded by Asahina, it was assumed that the above reaction passed through an intermediate of 5-trans-π-dihalo-d-camphor. Therefore, 5-bromo-trans-π-chloro-d-camphor was prepared from trans-π-chlorocamphor through trans-π-chloro-d-camphoquinone, trans-π-chlorodiazo-d-camphor, and trans-π-chloro-β-pericyclocamphanone. Application of fuming sulfuric acid to the 5-bromo derivative unexpectedly revealed that it is extremely stable to this acid and no change was found to occur. The same reaction of α-bromo-6-trans-π-dichloro-l-camphor showed that this substance is also stable to fuming sulfuric acid.

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Since there are many antibacterial substances such as chloramphenicol and Furacin which contain a nitro group, the effect of the nitro group to animals seemed of interest. In order to test the change, if any, of physiological action by the introduction of a nitro group in aromatic thiocyano compounds, a series of aromatic thiocyanonitro compounds were prepared. Of such compounds synthesized, the present paper describes 19 new compounds besides 2-ethoxycarbonyl-4-thiocyano-3′-nitrobenzanilide, 2-carboxy-4-thiocyano-4′-nitrodiphenylurea, and 2, 3′-dinitro-4-thiocyanobenzanilide.

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Biological activities of aromatic thiocyano compounds, substituted with nitro group in the ring or in the side chain, were tested against Staphylococcus aureus, Escherichia coli, and Rabdias bufonis. It was thereby found that antibacterial and rabdiacidal activities were present in compounds of the general formula, R₁ -SCN, in which R₁ is substituted with a fat-soluble group, such as -NHCONHC₆H₄NO₂ (p), and R₂ is substituted with an electrophilic and non-dissociating group, such as -NO₂ and -COOC₂H₅.

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Dried whole herb of Chrysosplenium japonicum Makino was extracted with methanol, the extract was treated with lead acetate, and a glycoside was obtained as yellow needles, m.p. 203° (melting once at 160°) in 0.7% yield. Its molecular formula agreed with C₂₄H₂₆O₁₃⋅1 1/2H₂O; [α]_D²³: -50.7°. Hydrolysis with 10% sulfuric acid afforded 1 mole each of a genin as yellow needles, m.p. 158-159°, C₁₅H₇O₅-(OCH₃)₃⋅1 1/2H₂O, and glucose. The glycoside was named chrysosplenin, and the genin, chrysosplenetin. Demethylation of chrysosplenetin gives quercetagetin, so that chrysosplenetin is quercetagetin trimethyl ether. Decomposition of chryso-splenetin with 3% hydrogen peroxide gives vanillic acid, and with 15% potassium hydroxide, vanillic acid and 4, 5-dimethoxyresorcinol are formed. Methylation of chrysosplenetin affords a dimethyl ether, m.p. 157-158°, and a trimethyl ether, m.p. 142-143°. The dimethyl ether agrees with the formula C₁₅H₅O₃(OCH₃)₅⋅1 1/2H₂O, and was found to be quercetagetin 3, 6, 7, 3′, 4′-pentamethyl ether by mixed fusion. It follows, therefore, that chrysosplenetin is quercetagetin 6, 7, 3′-trimethyl ether. The structure of chrysosplenin is chrysosplenetin-3 (or 5)-glucoside.

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Quercitrin was obtained in 2.5% yield from the leaves of Polygonum sachalinense Fr, Schm. (Reynoutria sachalinensis Nakai) and pale yellow needles, m.p. 203-204°, were obtained in 0.3% yield from the leaves of Polygonum Reynoutria Makino (Reynoutria japonica Houtt.). T he latter, C₂₁H₁₈O₁₁⋅3H₂O, was found to be quercetin-3-xyloside. This is a new substance and was named reynoutrin. Isoquercitrin or hyperin (quercetin-3-galactoside) is said to have been isolated from the leaves of Polygonum Reynoutyia, but substance corresponding to it was not obtained.

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A method was found to separatory detect cis and trans geometric isomers of urocanic acid by paper partition chromatography. By the utilization of this method, the cis isomer was isolated and purified from the sunlight irradiation product of the trans isomer, and the properties of the cis isomer were clarified. It was found by the examination of by-products formed during the synthesis of the trans isomer that a minute amount of the cis isomer is always present in it. Reversible photochemical conversion of trans to cis, and vice versa, was also examined.

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The structure of the two isomers, 5- and 7-methoxy-2-methylbenzothiazole, obtained by the alkaline ferricyanide oxidation of m-thioacetanisidide, was determined by comparative examination with 5-methoxy-2-methylbenzothiazole prepared from p-anisidine. Further, four kinds of hydroxy-2-methylbenzothiazole were prepared by the hydrolysis with hydriodic acid of four kinds of methoxy-2-methyl-benzothiazoles obtained to date, and it was found that it is possible to detect the hydroxyl in α-position of the benzothiazole ring by coloration, after submitting the four hydroxylated compounds to coloration by the Driver, ferric chloride, and ammoniac copper reactions.

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The structures of 5- and 7-chloro-2-methylbenzothiazole, obtained by the ferricyanide oxidation of m-chlorothioacetanilide were determined by the preparation of the 5-chloro derivative from 2, 5-dichloronitrobenzene through 4-chloro-2-amino-benzenethiol. The two isomers obtained by the ferricyanide oxidation of m-thioacetotoluidide were also structurally determined by the preparation of 2, 5-dimethylbenzothiazole by a similar route as above.

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Antibacterial action of auraptene and rapanone, α, β-unsaturated carbonyl compounds with about 10 carbon atoms in the side chain, were tested against pathogenic fungi, gram-positive and -negative bacteria, and acid-fast bacilli. It was found that auraptene is fairly effective against these microörganisms. While rapanone was found to be extremely antagonistic to SH compounds, auraptene was found to be ineffective.

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By the reaction of 4-methyl-5-β-chloroethylthiazole and thiourea, β-(4′-methyl-5′-thiazolyl) ethylisothiuronium hydrochloride was prepared and its oxidation with alkaline hydrogen peroxide yielded 4, 4′-dimethyldithiazolyl-5, 5′-diethyl disulfide dihydrochloride, m. p. 207-208°.

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Paper chromatography of chlorophyllin was carried out to examine the relationship between the reflectancy of the spot and amount of chlorophyllin. An approximate linear relationship was found to exist between the square root of the amount of chlorophyllin and the value of 2-log R, where R is the reflectancy, as was reported previously.

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As a new method of preparing dialkylaminoethyl esters of carboxylic acids, catalytic reduction of benzoylglycolonitrile, α-benzoyloxyisobutyronitrile, and diphenylacetylglycolonitrile, in the presence of dialkylamine, was carried out and the objective esters were obtained. High-pressure reduction of benzoylglycolonitrile with Raney nickel, under the same conditions, was found to cause the reduction of the ester to alcohol and benzyl alcohol was obtained.

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The presence of distylin (taxifolin) glucoside in the fresh leaves of Chamaecyparis obtusa var. breviramea Masters was found. Distylin has been found as its rhamnoside, astylbin, and its presence as a glucoside in the leaves of conifers is very interesting. The presence of distylin glucoside in the leaves of conifers plants other than the above may be expected.

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In order to prepare phenylhydroxylamine and its derivatives possessing alkyl group in the para-position, the representative Bamberger method was followed but the objective could not be attained. Further examination of his method was made to find optimal conditions for the neutral reduction of nitrobenzene and p-nitrotoluene with zinc powder and some defective points were corrected. It was also found that, if the reduction is carried out under the same conditions, p-nitrotoluene is far more easily reduced than nitrobenzene.

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A substance corresponding to lespedin (kaempferol-3, 7-bis-rhamoside) was obtained as pale yellow needles, m. p. 181-182°, in 0.6% yield from the terrestrial portion of Lotus corniculatus L. var, japonicus Regel. Pale yellow microneedles, m. p. 236-238°, were obtained in 0.15% yield from Microlespedeza striata Makino and was found to be luteolln-7-glucoslde. Rutin was obtained in 0.2% and 0.1% respective yield from the leaves of Magnolia obovata Thunb. and of Abutilon avicennae Gaertn.

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An identical glycoside was obtained in respective yields of 1.5%, 0.6%, and 0.35% from the leaves of Phaseolus angularis Wight, Ph. trilobatus Schreb., and Pueraria Thunbergiana Benth., as pale yellow, microneedles, m. p. 188-189° (decomp.). Its decomposition with 5% sulfuric acid afforded 1 mole of kaempferol, 2 moles of L-rhamnose, and 1 mole of D-galactose, and hydrolysis with 1% sulfuric acid gave 1 mole each of kaempferol-7-rhamnoside, L-rhamnose, and D-galactose. Decomposition with 10% barium hydroxide afforded colorless needles, m. p. 191-192°, which was found to be L-rhamnosido-D-galactose (probably robinobiose) bonded at 3-position. From the foregoing facts, this glycoside is known to be kaempferol-3-robinobio-7-rhamnoside and was found to be identical with robinin extracted from the flower of Robinia pseudacacia L. Kaempferol-3-rhamnoside is not present in the leaves of Pueraria Thunbergiana.

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High-pressure, catalytic reduction of saturated nitriles and cycloalkenylacetonitriles were carried out with U-Co-B catalyst, prepared from zinc powder and cobalt chloride in accordance with the preparative method for U-Ni-B. It was thereby learned that U-Co-B has approximately the same catalytic ability as that of Raney cobalt but can be prepared much easily and at cheaper cost.

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