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LXIX 24 674 H . 1. MII Hertog, J. C. M. Schogt, J. dt: B r u p arid Miss A. d e Klerk, _____-__.._____. ~ ~~ . ----___ .~1934"), 16 chloropyridines of known structure were described; three of the 19 possible chloropyridines, viz. the trichloroderivatives substituted in the 2,3,4-. 2.3.6-and 2,4,5-positions, were missing. Maier-Bode mentions along with the chloropyridines of known structure, three other substances belonging to this group, which are mentioned in the literature but of which the structure had not been established, viz. a trichloropyridine. m.p. 71-72", obtained by Kciser by the action of chlorine on pyridines); a compound meiting a t 64-65", which was obtained in small quantity by Seyfferth by the action of phosphorus pentachloride on nicotinic acid followed by treatment with 80 yo sulphuric acid and which he considered to be a trichloropyridine 4, ; a trichloro-Fyridine, m.p. 6 7 -4 8 " , obtained by Sell and Dootson by chlorinating pyridine with phosphorus pentachloride 5 ) .Keiser's trichloropyridine was identified in 1905 as 3,4,5-trichloropyridine by Sell and Dootson 'j). Maier-Bode apparently missed this. Nicolai' 7 ) has already mentioned this fact when he was handling the chloropyridines in connection with an investigation which he carried out in collaboration with Wibaut on the chlorination of pyridine in the gas phase 8).Nicolai also indicated that the properties of the trichloropyridine, m.p. 67--68", prepared by Sell and Dootson, made it probable that the chlorine atoms in this substance were in the 2, 3 and 6-positions'). In the meantime, this conclusion has been confirmed by Crouch and Lochte, who have synthesised this trichloropyridine by reacting glutarimide with phosphorus pentachloride @) .W e have repeated the$ chlorination of nicotinic acid described by Scyffeerth. Instead of a small quantity of a trichloropyridine, we have obtained a complex mixture of chloropyridines in which the presence of 2,3,5.6-tetrachloropyridine could be detected. We assume now that Seyfferfh had a little 2.3,6-trichloropyridine in his hands on the basis of the melting point of his product and the fact that substitution in nicotinic acid occurs apparently in both a-and &positions l o ) .While Maier-Bode's book was being printed, Graf prepared 2,3,4-trichloropyridine From 4.5.6-trichloropyridine-2-carbonyl chloride j l ) . ) H. Maier-Bodeand 7. Alfpefcr, "Das Pyridin und seine Derivate in Wissen-3) E. H. Keiser, Am. Chem.

A series of 2,6-pyrido crown ethers with ring sizes of 15-33 ring atoms has been synthesized. Their complexation with guanidinium salts has been studied by using two phase extraction experiments. The crystal and molecular structures of 2,6-pyrido-27-crown-9-guanidinium perchlorate (l:l), 2,6-pyrido-30-crown-lGguanidinium perchlorate (l:l), 2,6-pyrido-27-crown-9-guanidinium thiocyanate-ethanol (2:3:1), 2,6-pyrido-27-crown-9-picric acid (l:l), and the free 2,6-pyrido-24-crown-8 have been determined by X-ray crystallography. In the free and protonated crown ethers, the cavity is occupied by the aromatic ring of the crown ether. In the complexes with guanidinium salts the guest molecule is encapsulated within the cavity, using all its hydrogen atoms for H-bonding between host and guest. The best fit for the guanidinium ion is found for the 27-membered macrocycle with a complementary host-guest H-bonding scheme. Crown ethers with 18 ring atoms form perching complexes.

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In connection with pharmacological properties ascribed to the seeds of Celastrus paniculatus Willd. (Hindi: Malkanguni), a plant mentioned in old Indian medical literature, the composition of the components of these seeds has been studied. In 1938, Gunde and Hilditch 1) investigated the fat of the aril-free seeds of Celastrus paniculatus and, by extraction with 80% MeOH aq., segregated it into glYceride and non glyceride fractions. From the latter fraction, these authors isolated, after saponification and acetylation of the neutral part, a resinous product which on the basis of element analysis , was considered to be the tetra-acetate of a tetrahydroxylic alcohol with an approximate composition ClSH2SOS. The nature of this compound(s), however, could not be defined. Some years ago, a more detailed investigation of this polyalcohol mixture was undertaken, independently, by two different groups, in Indiaa) and in the Nether-lands3). We find that several polyhydric alcohols are present and now report on the structure of one of the major constituents.