Among four stereoisomers (IXa, Xa, XIa, XIIa) of hydrofluorene derivatives recently derived from pine rosin, only IXa has a strong sweetness (ca. 1000 times sweeter than sucrose and ca. 12 times bitterer than caffeine) and others have no taste. Stability and acute toxicity of IXa were also examined.
Reaction of 1-acetyl-3-hydroxy-2-(2-methoxycarbonyl-1-methylthiovinyl)indole derivatives (Ia-d) and amines afforded the corresponding amino derivatives (V and X) with 4-aminopyrano[3, 2-b]indol-2-one derivatives and 2-amino-3H-pyrrolo[1, 5-a]indol-3-one derivatives. Application of hydrazine hydrate to Id gave a compound (XII) with pyrazolone in α-position of indole. Reaction of Id with diethylamine gave 9-amino-1-methylthio 3H-pyrrolo[1, 5-a]indol-3-ones (XI), while the reaction of Ie with amines gave 1, 9-di-amino-3H-pyrrolo[1, 5-a]indol-3-one derivatives (XIVa, b).
1-Acetyl-3-indolinone was reacted with N-bis(methylthio)methylenebenzenesulfonamides in the presence of a base and it was found that the reaction differed accodring to reaction conditions. Reaction of 3-indolinone derivative (V, VII) with nucleophilic reagents such as amines and active methylenes afforded substitution products corresponding to the reagent used. By the use of these products, indole-condensed ring compounds, 1-(p-toluenesulfonylamino)-9-(p-toluenesulfonyloxy)pyrazino[1, 2-a]indole (IX) and 1-(p-toluenesulfonylamino)-3H-pyrrolo[1, 2-a]indol-3-one (XI), were synthesized.
Reaction of ethyl isothiocyanatoformate (II) with o-aminobenzenethiol (Ia) affords ethyl 4-(o-mercaptophenyl)-3-thioallophanate (IIIa), which is readily converted into ethyl 2-benzothiazolecarbamate (IVa), with desulfurization, by heating. Ethyl 4-(o-aminophenyl)-3-thioallophanate (IIIb) and ethyl 4-(o-hydroxyphenyl)-3-thioallophanate (IIIc), which do not afford any cyclization product in aprotic solvents, can also be cyclized to ethyl 2-benzimidazolecarbamate (IVb) and ethyl 2-benzoxazolecarbamate (IVc), respectively, by heating in strongly protic solvents. Heavy metal ions and/or hydrogen peroxide, which are known as soft acids, accelerate desulfuric ring-closure reactions in the presence of basic anions.
A new tricyclic ring system, dibenz[b, g][1, 5]oxazocine derivatives (VIII), was synthesized. In this reaction, a 16-membered ring compound (IX) was obtained as a byproduct besides the objective VIII, and formation ratio of these two compounds varied with reaction conditions. Catalytic reduction of the 6-benzyl compound (VIII-5) gave 6, 7-dihydro-5H-dibenz[b, g][1, 5]oxazocine (X) and various derivatives of X were prepared. 6-(ω-Alkylaminoalkyl)-6, 7-dihydro-5H-dibenz[b, g][1, 5]oxazocines (XXVI) and 5, 13-bis(ω-dialkylaminoalkyl)-2, 3-, 7, 8-, 10, 11-, 15, 16-tetrabenzo-1, 9-dioxa-5, 13-diazacyclohexadeca-2, 7, 10, 15-tetraenes (XXVII) were synthesized.
New tricyclic dibenz[b, g][1, 5]thiazocine derivatives (III) were synthesized by the route shown in Chart 1. In this condensation reaction, a 16-membered ring compound (IX) formed as a by-product, the formation ratio of which varied under reaction conditions. Heating of dibenzylamine (X) with sulfur afforded thiobenzoylbenzylamine(XII) and not 6, 7-dihydro-5H-dibenz[b, g][1, 5]thiazocine (XI). 6-(ω-Alkylaminoalkyl)-6, 7-dihydro-5H-dibenz[b, g][1, 5]thiazocine (XVIII) derivative was synthesized by the route shown in Chart 4.
Condensation of bis(2-bromomethylphenyl) sulfoxide (VI) or sulfone (VII) with primary amines afforded dibenz[b, g][1, 5]thiazocine oxides (II or III). In this reaction, by-product formation of a bimolecular compound (IV), as was the case in the reaction of bis(2-bromomethylphenyl) sulfide (V), was not observed. Catalytic reduction of 6-benzyl-6, 7-di-hydro-5H-dibenz[b, g][1, 5]thiazocine 12, 12-dioxide (5) afforded 6, 7-dihydro-5H-dibenz-[b, g][1, 5]thiazocine 12, 12-dioxide (XI). The benzyl protons at 5- and 7-positions in II and III appear in their nuclear magnetic resonance spectrum as an AB-type double doublet. 6-(Alkylaminoalkyl)-6, 7-dihydro-5H-dibenz[b, g][1, 5]thiazocine oxides (XIII) were synthesized by the route shown in Chart 3.
Condensation of 4-chloro-2, 2'-di(bromomethyl)diphenyl ether (X) and ω-aminoalcohol (XI) gave 3-chloro-6-(ω-hydroxyalkyl)-6, 7-dihydro-5H-dibenz[b, g][1, 5]oxazocine (XII), with a 16-membered ring dimer (XIII) as a by-product. The formation ratio of these two products varied with reaction conditions. 3-Chloro-6(ω-alkylaminoalkyl)-6, 7-dihydro-5H-dibenz[b, g][1, 5]oxazocine (XV) was also synthesized.
Methyl 1-cyano-2-methylthio-3-nitrocrotonate was reacted with hydrochloric acid under various conditions and 2, 5-dihydro-2-hydroximino-5-imino-4-methoxycarbonyl-3-methylthiofuran monohydrochloride, 2, 5-dihydro-2-hydroximino-4-methoxycarbonyl-3-methylthiofuran, and α-methylthio-β-methoxycarbonylmaleic anhydride were synthesized. The mutual relationship of these products was clarified.
Carbon-13 nuclear magnetic resonance (NMR) spectra of nine kinds of mono-substituted barbituric acid derivatives were measured. Two conclusions were obtained from the analysis of carbon-13 NMR spectra. (1) The so-called additive law is applicable to chemical shifts of the carbon at 5-position. (2) There is a correlation between chemical shifts of the carbon at 5-position and pKa, values, except in barbituric acid and 5-methylbarbituric acid.
Reaction of various kinds of nitroquinoline with hydroxylamine in potassium hydroxide alkalinity afforded a novel product, furazanoquinoline, besides the known amino derivatives. The products obtained were furazano[3, 4-f]quinoline (XII) from 5-nitroquinoline (VIII) and 6-nitroquinoline (XIII), and furazano[3, 4-h]quinoline (XVII) from 7-nitroquinoline (XV) and 8-nitroquinoline (XVIII). The same reaction progresses with 3-nitroquinoline (II) but the nitro group is substituted with the reagent in the case of 4-nitroquinoline (V). 6, 8-Diamino-5-nitroquinoline (XI) obtained by the reaction of VIII with hydroxylamine was found to be formed via 6-amino-5-nitroquinoline (X).
Reaction of 5-nitroquinoline (I) with hydroxylamine was examined and the following reaction mechanism was presumed. In X, the ring hydrogen at the position to which hydroxylamine has added, makes a proton shift to both the nitrogen in the hydroxylamino group and oxygen in the nitro group, and two kinds of reaction progresses. The former reaction route (path a) produces 6-amino derivative (III) and the latter route (path b) gives furazano[3, 4-f]quinoline (VIII). The N-O bond in hydroxylamine is cleaved by the reaction of path a but remains in the molecule by the reaction of path b. In contrast, the N-O bond in hydroxylamine-O-sulfonic acid tends to be severed by the effect of the sulfo group and its reaction with I produces a large quantity of III, with only a minute amount of VIII. When the site of the reaction with reagents is conjugated with the ring-nitrogen in quinoline, formation of furazan compound is small.
The reaction of ketene acetals (IIa-d) with primary amine (Ia-j) gave imino ether derivatives (III) in a good yield. Benzylamine (Ia) reacted with ketene acetals (IIa-c) to give amidine derivatives (IV), besides the formation of III. Reaction of p-nitroaniline (Ic) with IIa gave ethyl N-(p-nitrophenyl)acetimidate (IIIca) and ethyl N-(p-nitrophenyl)-3-ethoxycrotonimidate (VI). 4-Aminopyridine l-oxide (Ij) reacted with IIa to give ethyl N-(4-pyridyl 1-oxide)acetimidate (IIIja) and ethyl N-(4-pyridyl)acetimidate(IIIga). On treatment with dilute acid, III were hydrolyzed into amines, amidines, esters, and amides.
The reaction of 5, 8-dimorpholino-2-phenyl-3, 4-dihydropyrimido[4, 5-d]pyridazine (IIa) with equimolar benzyl bromide and sodium hydride afforded 1-benzyl-5, 8-dimorpholino-2-phenyl-1, 4-dihydropyrimido[4, 5-d]pyridazine (IIIa), accompanied by a small amount of 3-benzyl-5, 8-dimorpholino-2-phenyl-3, 4-dihydropyrimido[4, 5-d]pyridazine (IVa). When IIa was treated with two equimolar benzyl bromide and sodium hydride, 1, 4-dibenzyl-5, 8-dimorpholino-2-phenyl-1, 4-dihydropyrimido[4, 5-d]pyridazine (Va) was formed in a good yield, which was converted to 4-benzyl-5, 8-dimorpholino-2-phenyl-3, 4-dihydropyrimido[4, 5-d]pyridazine (VIa), a diuretic agent, by hydrolysis with 10% HCl.
Several chemical reactions of epoxylathyrol3, 4) (I) were investigated. Catalytic hydrogenation of I gave dihydro I compound, mp 65-68°. Treatment of I with perbenzoic acid gave an epoxy derivative (III), mp 198-200°. Mild alkaline hydrolysis of I yielded a triol, mp 207-209°, C20H30O5·H2O, which readily underwent addition with diazomethane to give a pyrazole derivative, mp 100-102°, C21H32O5N2·H2O. Treatment of I with oxalic acid in glacial acetic acid gave a product (IX), mp 207-209°, C33H42O10·H2O, which exhibited a free hydroxyl absorption at 3450 cm-1 and lost the conjugated carbonyl group in its infrared spectrum. In the nuclear magnetic resonance spectrum of IX, a methyl group attached to the double bond and the olefinic proton disappeared, and three acetyl groups appeared at δ1.99, 2.04, and 2.21, indicating that one new acetyl group was formed. The methine carrying the new acetyl group, appeared as a doublet at δ4.62 (J=8.0 Hz), indicating a partial structure of [chemical formula]. The spectral properties could be explained with structure IX. This acid-catalyzed transannular cyclization would be initiated by a nucleophilic attack to yield an intermediate (IX-A), which would undergo cleavage of the epoxy ring (IX-B) followed by transannular addition to give compound IX. On the other hand, treatment of I with hydrogen halides in tetrahydrofuran gave the corresponding halides, C32H41O8Cl (VII), mp 219-221°, C32H41O8Br (VIII), mp 175-178°, whose epoxy ring would be opened and hydrogen halide added to it.
An asymmetric synthesis of α-amino acids was attempted through Neber rearrangement of (-)-menthyl N-chloroimidate by treatment with a base. As a result, L-phenylglycine, L-alanine, L-phenylalanine, and L-leucine were obtained, optical purity of the isolated products being 27%, 33%, 62%, and 75%, respectively. The asymmetric induction occurred to a much less extent, when (-)-2-methyl-1-butanol was used in place of (-)-menthol.
Dimethyloxosulfonium benzoylmethylide and dimethylsulfonium benzoylmethylide were found to react with quinoline 1-oxide in the presence of an acylating agent, producing dimethyloxosulfonium 2-quinolylbenzoylmethylide and dimethylsulfonium 2-quinolylbenzoylmethylide, respectively. Similar reaction products were obtained by the reaction of dimethyloxosulfonium benzoylmethylide with 4-methylquinoline 1-oxide, isoquinoline 2-oxide, and quinoxaline 1-oxide, but not with pyridine 1-oxide.
The present experiment was carried out to obtain some information regarding formation mechanism of crystalline inorganic components in plants, using the "low-temperature plasma ashing method for biological materials" originated with K. Umemoto. The crystal image in a leaf was followed through its life cycle and difference in the life cycle to various tissue cells in the same plant was examined. The sample material was a leaf (minus the petiole) from weeping willow (Salix babylonica LINN.), measuring about 6 to 128 mm in length, collected during March to June in Kyoto city. The crystal image of calcium oxalate that appears with growth of the leaves was followed. It was thereby found that the crystal form of calcium oxalate that appears first in the willow leaf is an aggregate, and that solitary crystals appear after a certain period. In addition, the pattern of crystal distribution in the costa, mesophyll, apex, and margin of the leaves at different periods of observation was found to change markedly. Examination must be made in future on the correlation, if any, between this change in the pattern and physiology of the plants.
From the leaves of Callicarpa japonica THUNB. and C. japonica THUNB. var. luxurians REHD., 4', 5, 6, 7-tetramethoxyflavone (II) was isolated and it was found to have fish-killing activity. Its toxicity to Oryzias latipes TEMMINCK et SCHLEGEL was found to be one-half of that of 5, 6, 7-trimethoxyflavone (I).