Orange Needles Research Articles

防已科植物アルカロイド研究 第160報

Examination, of alkaloids and steroids in Sinomenium acutum REHD. FT WILS. afforded a tertiary phenolic base, isosinomenine (I), and a substance containing nitrogen, forming orange yellow needles, m.p. 201-202°, as the new bases, and β-sitosterol and stigmasterol as the steroids.

ベンツオイン縮合 (第4報)

Benzothiazoin was prepared by the action of KCN on 2-formylbenzothiazole, which crystallizes from xylene as orange needles, m.p. 280-282° (decomp.). Oxidation of benzothiazoin by bromine or air yields benzothiazil (I), m.p. 245°. Carbonyl reagent does not react with benzothiazoin while Tollen's reagent and 2, 6-dichloroindophenol are reduced by it. In the absorption spectrum of benzothiazoin a peak appears at 406mμ, while the peaks in the absorption spectra of its diacetate and its dibenzoate shift to 365mμ, as in the case of quinaldoin dibenzoate, probably due to the loss of hydrogen bonding by acylation. Di (benzothiazolyl-2)-ethylene, m.p. 225-226°, which was prepared from 2-methylbenzothiazole and 2-formylbenzothiazole, shows a peak at 368mμ in the absorption spectrum. From the above results a structural formula (II) is proposed for benzothiazoin. The absorption curve of benzothiazoin in pyridine solution is quite different from that in chloroform solution, while the absorption curve of quinaldoin in pyridine solution is similar to that in chloroform solution. This is probably because the basicity of benzothiazole is less than that of quinoline and the hydrogen bonding of benzothiazoin is weaker than that of quinaldoin.

1,4-ナフトキノン2位及び2,3位置換体の抗菌性 (第2報)

Antibacterial activities were tested with 2-propylmercapto-, 2-butylmercapto-, 2-allylmercapto-, 2-thiophenyl-, 2-p-thiocresyl-, 2-p-chlorothiophenyl-, 2-methylamino-, benzylamino-, 2-anilino-3-chloro-, 2-anilino-3-methylmercapto-, 2, 3-di(thiophenyl)-, 2, 3-di-(p-thiocresyl)-, 2, 3-dichloro-, and 2-chloro-3-hydroxy-1, 4-naphthoquinone, and results are shown in Tables I and II. There were no compounds that showed better results than 2-methylmercapto-and 2, 3-di(methylmercapto)-1, 4-naphthoquinone, reported in the previous paper, but dichloro- and allylmercapto-1, 4-naphthoquinone were found to possess a fair degree of antibacterial power. 2, 3-Di(thiophenyl)-1, 4-naphthoquinone gives two kinds of crystals according to the conditions of recrystallization, one of purple leaflets, and the other of orange red needles, m.p. 148°. The former was found to transit to the latter without melting at 100-105° to orange red crystals that melt at 148°.

P-Hydroxybenzil

BY oxidizing p-hydroxydeoxybenzoin with chromic anhydride in acetic acid, Weisl1 obtained a substance, m.p. 175°, which he claimed to be p-hydroxybenzil. He described it as an amorphous powder, crystallizable with difficulty from aqueous ethanol in the form of orange needles ; in alcoholic solution, it gave a deep red colour with potassium hydroxide.

On the formation of a heat-reversible gel

In the course of his study of the cyclic ketonic compounds, Dr. Ruhemann has discovered a substance which is, I think, destined to play an important part in the development of the theory of gelation. The substance is 5 dimethylaminoanilo-3:4 diphenylcyclopentene-1:2 dione,* the formula, being C 6 H 5 C―C:NC 6 H 4 N(CH 3 ) 2 ‖ | C 6 H 5 C CO ⁄ CO It is a solid at ordinary temperature, and occurs either as orange-coloured needles or as small dark red plates; the former separate from dilute solutions, the latter from concentrated solutions in absolute alcohol. “If a little water is added to the hot alcoholic solution, no crystals separate on cooling, but the whole sets to a transparent jelly, which, according to concentration, is yellow or yellowish-red. This gel, when kept at the ordinary temperature, gradually liquefies, and in the course of one or two days completely disappears, with separation from the resulting solution of the azomethine in orange needles.” Dr. Ruhemann has therefore furnished us with a substance which offers special facilities for studying the relations between the crystalline and the colloidal state.