Hydrogen Chloride In Ether Research Articles

Polysilylation de nitriles aromatiques à partir de chlorosilanes: synthèse d'énamines

The trimethylchlorosilane/magnesium/hexamethylphosphorictriamide system reacts with aromatic nitriles to give enamines. The silylation occurs both on the nitrile function and on the aromatic ring. It begins at the position ortho to the nitrile function of 1-and 2-naphthonitrile, and para to that of benzonitrile. This latter gives a pentasilylated enamine while tetra- and hexasilylated enamines are obtaine from 1-naphthonitrile; with 2-naphthonitrile we isolate two hexasilylated isomers. One of them, by further silylation and after rearrangement of the intermediate enamine, gives an amine including eight SiMe 3 groups. Through hydrolysis some enamines lead to aldehydes while others, treated by hydrogen chloride in ether, give amines. Further, for one of these amines we observe a rearrangement of SiMe 3 groups. A mechanism is proposed to give an explanation for these reactions.

Unexpectedly low reactivity for spirosilanes: 4-sila-spiro[3,3]heptane

Competitive cleavages of 4-silaspiro[3,3]heptane (I), 4-silaspiro[3,5]nonane (III), and 1,1-dimethylsilacyclobutane (III) by hydrogen chloride in diethyl ether have been carried out; the unexpectedly low reactivity of (I) is discussed in terms of a model controlled by steric considerations.

Studies on the constituents of Lyonia ovalifolia Drude var. elliptica Hand.-Mazz. XIV. Structure of diterpenoid, lyoniol-A (lyoniatoxin). (3)

Ketolyoniol-A (II) was hydrolyzed to 7-ketolyoniol-B (III) which, on treatment with p-toluenesulfonic acid in acetone, yielded a monoisopropylidene derivative (IV). The carbonyl group in IV was reduced with lithium aluminum hydride to an alcoholic hydroxyl group as shown in formula (V). Therefore, the isopropylidene residue in IV should be attached to C-5 tertiary and C-6 secondary alcoholic oxygens to form a dioxolane ring. This result proves the presence of C-5 OH grouping in lyoniol-A (I). Lyoniol-B (VI) consumes only one mole of sodium periodate. On the basis of nuclear magnetic resonance (NMR) and mass spectral data, the oxidation product was assigned (VII), which is predicted not to consume sodium periodate. The epoxide ring of ketolyoniol-A (II) was opened with dry hydrogen chloride in ether to afford a chlorohydrin derivative (X), which was converted to a diketone (XII) by subsequent chromic acid oxidation. The positions and configuration of Cl and OH group in X have been elucidated as 2α and 3β, respectively, on the basis of infrared and NMR analyses of X, XI, and XII, and optical rotatoly dispersion measurements of IX, X, and XII. Consequently, configuration of the epoxide ring in lyoniol-A was determined as β. Further lyoniol-A furnished 2-acetoxydihydrolyoniol-B tetraacetate (XIII) with acetic anhydride and pyridine at 60-70°. Previously reported dihydrolyoniol-B triacetate (XV) has been revised to tetraacetate (XIV) on the basis of NMR study and three partially hydrolyzed products of XIV were synthesized in this connection.

The chemistry of nitro-compounds. Part I. Acid-catalysed ring-opening reactions of substituted o-nitrophenylethylene oxides involving participation by the nitro-group

Ethereal hydrogen chloride converts trans-1-acetyl- and 1-benzoyl-2-(o-nitrophenyl)ethylene oxides (1c and a) in low yield into the corresponding 6-chloro-1,3-dihydroxyquinolin-4-ones (2a and c). In contrast, reaction of the cis-benzoyl epoxide (1b) or of the 1,1-diacylethylene oxides (1d and e) with ethereal hydrogen chloride affords high yields of the compounds (2a and c). In the presence of hydroquinone these reactions give the chlorine-free 1,3-dihydroxyquinolones (2b and d). The course and mechanism of the reactions are discussed.Manganese dioxide oxidation of the 1-hydroxyquinolones (2a—d) and of the reduction products (3a and b) affords the hitherto unknown quinoline-3,4-quinones (7a—d) and (8a and b).

Reaction of 2,3-epoxy-3-(2-nitrophenyl)propiophenone(2-nitrochalcone epoxide) with hydrogen chloride

The reaction of 2,3-epoxy-3-(2-nitrophenyl)propiophenone(2-nitrochalcone epoxide) with ethereal hydrogen chloride gives 6-chloro-1,3-dihydroxy-2-phenylquinolin-4(1H)-one; the corresponding unchlorinated product is obtained in the presence of quinol.

Participation by the nitro-group in the ring-opening reactions of substituted o-nitrophnylethylene oxides

Ethereal hydrogen chloride converts substituted o-nitrophenylethylene oxides into products identified as tautomeric 3,4-dihydro-1,3-dihydroxy-4-oxoquinoline derivatives: a course for these reactions involving participation by the nitro-group in the acid-catalysed opening of the epoxide ring is discussed.

Polyfluoroheterocyclic compounds. Part XV. Formation and nucleophilic substitution of polyfluoropyridazinium cations

Under strongly acidic conditions, nucleophilic attack on tetrafluoropyridazine and on 3,5,6-trifluoro-4-methoxypyridazine by water or methanol leads to substitution of the fluorine atoms at C-3 and C-6 in preference to those at C-4 and C-5 which have previously been shown to be more reactive towards nucleophilic reagents under basic conditions. Treatment of tetrafluoropyridazine with water in sulphuric acid solution gives 3,4,5-trifluoro-1H-pyridazin-6-one, and similar treatment with methanol gives 3,4,5-trifluoro-6-methoxypyridazine (at 0°) or 4,5-difluoro-3,6-dimethoxypyridazine (at 20°). All four fluorine atoms of tetrafluoropyridazine are replaced by chlorine when it is treated with ethereal hydrogen chloride at 18°. Spectroscopic evidence suggests that the acid-catalysed reactions involve nucleophilic attack on protonated polyfluoropyridazinium cations, and two N-alkyl-tetrafluoro-pyridazinium tetrafluoroborates have been prepared and shown to give exclusively 1-alkyl-3,4,5-trifluoropyridazin-6-ones on treatment with water. Factors affecting the orientation of the products of nucleophilic attack on poly-fluoropyridazinium cations are discussed. Structures have been assigned to the two isomeric difluoromethoxy-pyridazinones resulting from the acid-catalysed hydroxylation of 3,5,6-trifluoro-4-methoxypyridazine, by relating them to 3,4-difluoro-5,6-dimethoxypyridazine and 3,5-difluoro-4,6-dimethoxypyridazine.

The four trans chlorohydrins of 3-methoxycyclohexene

trans-3-Methoxycyclohexene oxide (II), when treated with ethereal hydrogen chloride, gives the chlorohydrin dl-1α-chloro-2β-hydroxy-3α-methoxycyclohexane (IVa), and the cis oxide III gives dl-1β-chloro-2α-hydroxy-3α-methoxycyclohexane (Va). The point of scission of the oxide ring (remote from the methoxyl) is therefore the same as in other reactions observed by ourselves and others. The reaction of 3-methoxycyclohexene (I) with N-chlorosuccinimide and water at 100° gives three chlorohydrins: dl-1β-chloro-2α-hydroxy-3α-methoxycyclohexane (VI), dl-2β-chloro-1α-hydroxy-3α-methoxycyclohexane (VIa), and dl-2α-chloro-1β-hydroxy-3α-methoxycyclohexene (VIIa) (approximately in the ratio 10:38:50, respectively). Two of the chlorohydrins were solids, and the homogeneity of the liquid isomers was demonstrated in several ways. The structures were proven by the nuclear magnetic resonance spectra of the p-nitrobenzoates, and by chemical methods. The results are of considerable interest with regard to the theory of addition and substitution reactions. There is a close parallel with the results in the bromohydrin series.

Cadmium derivatives of decaborane

Diethylcadmium (Et2Cd) reacts with decaborane (B10H14) in ether solvents to form CdB10H12,2S (where S is diethyl ether or tetrahydrofuran). This compound is thought to be the first example of a neutral, 6,9-internally-bridged derivative of B10H14(2802 topology) and contains direct Cd–B bonds. The cadmium borane reacts quantitatively with ethereal hydrogen chloride to give decaborane and cadmium chloride, and ionises in aqueous solution to yield the novel dianion [(B10H12)2Cd]2–. The properties and structures of these compounds are discussed.

Organometallic chemistry of the transition metals : XII. Some alkoxycarbonyl derivatives of the cyclopentadienylmetal carbonyls

Reaction between (CH 3) 2NCOFe(CO) 2C 5H 5 3 and methanol gives the yellow-orange methyl ester CH 3OCOFe(CO) 2C 5H 3. Cleavage of this iron-containing ester with hydrogen chloride in ether or benzene solution gives the yellow hygroscopic salt [C 5H 5Fe(CO) 3][HCl 2]. Reaction between CH 3OCOFe(CO) 2C 3H 5 and the alkylmagnesium bromides RMgBr (R = methyl or phenyl) gives the acyl derivatives RCOFe(CO) 2C 5H 5 previously prepared from NaFe(CO) 2C 5H 5 and acyl halides 3,10.

79. Hydrogen bonding in gaseous mixtures. Part I. Infrared spectra of ether–hydrogen chloride systems

79. Hydrogen bonding in gaseous mixtures. Part I. Infrared spectra of ether–hydrogen chloride systems

Some reactions of substituted 2′-benzyloxychalkone epoxides

The behaviour of 2′-benzyloxychalkone epoxides towards acid reagents depends on the presence of substituents in the styryl part as well as on the reaction conditions. Ethereal hydrogen chloride under various conditions have been generally used but acetic acid alone or in conjunction with hydrobromic acid have also been used in a few cases. Simple 2′-benzyloxy-(I) and 2′-benzyloxy-4′-methoxy-(XIV) chalkone epoxides give only dihydroflavonols II and XV respectively; whereas 12′-benzyloxy-4-methoxy-(XIX) and 2′,4′-dibenzyloxy-4-methoxy-(III) chalkone epoxides give various products depending on the conditions. From the latter epoxide (III), chlorohydrin (VI), glycol monoacetate (IX), 1,2-diketone (IV), and isoflavones (VII and VIII) have been isolated.

Naturally occurring epoxy acids: ii. detection and measurement of long-chain epoxy acids by near infrared spectrophotometry

A new method for the detection and estimation of long-chain epoxy acids in seed oils is described. It depends on the measurement of increased absorption at 2.795 μ in the near infrared spectrum caused by chlorohydrins produced from epoxides by treatment with anhydrous ethereal hydrogen chloride. The method is sensitive to approximately 0.2% of epoxy acid in an oil and is specific for epoxides. Hydroxy components of a sample do not interfere since the strongly associated hydroxyl band of chlorohydrins is normally clearly resolved from other OH absorption. The presence of large amounts of vicinally unsaturated hydroxy acids, however, results in large changes in absorption intensity in the 2.8 μ region on HCl treatment and in these cases epoxide concentration cannot be accurately measured but must be estimated. These reactive hydroxy acids, which lead to spurious epoxide values by the conventional methods, lose hydroxyl during the acid treatment, and measurement of the decrease in their absorption at 2.762 μ means that their concentration may be estimated concurrently with that of epoxy components. Other reactive acids, such as cyclopropenoid acids, which result in high epoxide values by the usual methods, do not interfere. Results obtained by this spectrophotometric method are compared, for some oils, with those obtained by the usual chemical methods of epoxide determination.

Vicinally unsaturated hydroxy acids in seed oils

SummaryThe interference of certain unsaturated hydroxy acids in the Durbetaki method of epoxide determination has been demonstrated. The concentrations of these constituents were determined concurrently with those of epoxy components by measurement of the near infrared spectra of samples before and after treatment with anhydrous ethereal hydrogen chloride. The individual hydroxy esters were separated and isolated from samples of mixed esters by thinlayer chromatography. GLC of these esters resulted in their alteration to conjugated trienoates and gave proof of their conjugated diene hydroxyl structure. Thin‐layer chromatographic and infrared studies verified theTrans‐trans diene unsaturation of the acid fromDimorphotheca aurantiaca oil and showed that the other hydroxy compounds examined have acistrans diene system. These data suggest that the seed oils ofArtemisia absinthium, Calliandra eriophylla, Balanites aegyptica, Cosmos bipinnatus, and Helianthus annuus contain 9‐hydroxy‐trans‐10‐cis‐12‐ and 13‐hydroxy‐cis‐9‐trans‐11‐octadecadienoic acids.

TWO-COMPONENT SYSTEMS INVOLVING COMPOUND FORMATION

The two-component systems ethyl ether-hydrogen chloride and methyl alcohol-hydrogen chloride have been examined in the gaseous state, and from the pressure-volume-temperature relationship of the binary mixture evidence is adduced of the existence of compound formation. The heats of reaction appear to be constant in the temperature range investigated, and are 5400 calories for the ether hydrochloride, and 9200 calories for the alcohol hydrochloride. The pressure-volume-temperature data for ethyl ether, methyl alcohol and ethyl alcohol are given over the temperature range 50–200 °C., and over the pressure range below one atmosphere.