Oxalyl derivatives

The carbanion derived from isopropyl dichloroacetate adds on to 5a-cholestan-3-one to give the 3/3-hydroxy-3 -carboxydichloromethyl derivative (148) under kinetic control, or the a-chloroglycidic ester (149) under thermodynamic control.151 The latter compound rearranges in refluxing dioxan to give the 3/3-chloro-3a-oxalyl derivative (150). 

Four-membered peroxides are an interesting group of compounds, and will be discussed briefly. Such compounds have the ability to yield excited state carbonyl fragments upon thermolysis 154 in such cases, chemiluminesence is often observed. A classic illustration of this type of chemistry is the reaction of hydrogen peroxide with oxalyl derivatives, for example, when the 2,4-dinitro-... 

Lespagnol prepared iV-alkylphenothiazines using oxalic esters. In this reaction, the formation of 10-alkoxalylphenothiazines (138) is expected since esters usually convert secondary amines into amides. It might be supposed that 138 is thermally decomposed in a way similar to the phenothiazine-lO-carboxylate esters (136), the decarboxylation being here accompanied by decarbonylation, a common occurrence with oxalyl derivatives (Scheme 15). 

Oxalyl - p - aminophenylarsinic acid, COaH.CO.NH-CgHgAsO (011)2. — mixture of 347 grams of sodium p-arsanilate and 378 grams of crystallised oxalic acid are heated at a temperature of 120° to 180° C. until the bulk of the water is driven off, the temperature then being slowly raised to 160° C., until the mass becomes pulverulent. After cooling, it is mixed with 3000 e.c. of water, 390 c.c. of hydrochloric acid (density 1 12) are added and the mixture stirred for thirty minutes. The crude product is dissolved in 700 c.c. of cold water and 200 c.c. of 7N sodium hydroxide, the filtered solution being treated with 890 c.c. of hydrochloric acid (density 1 12) to precipitate the oxalyl derivative. The latter is a white powder, unmelted at 860° C., soluble in hot water, alkali hydroxide and carbonate, insoluble in acids and sparingly soluble in methyl alcohol. 

The oxalyl derivative is formed by heating the sodium salt of the acid with oxalic acid, first at 140° C., then at 160° C. It crystallises from 50 per cent, acetic acid in elongated, rhombic prisms. When nitrated with mixed acid it is converted into 5-nitro-4-amino-8-methyIphenyl-arsinic acid (p. 268). ... 

AminophenyIarsinie acid is converted into its oxalyl derivative, which crystallises from water in needles. This product, in 3 parts of concentrated sulphuric acid at 0° to 5° C., is treated with the requisite amount of nitric acid (26 per cent.), stirred at the ordinary temperature, and the liquid poured upon ice. Tire precipitated nitro-compound is boiled with 10 parts of 2N hydrochloric acid, the required arsinic acid separating in yellow needles on cooling. Boiling With concentrated potassium hydroxide converts the acid into 6-nitro-3-hydroxyphenyl-arsinie acid. In the mother-liquors of the foregoing nitration a very small quantity of 2-nitro-3-aminophenylarsinic acid is present. 2-Nitro-4-aminophenylarsinic acid, ... 

C.C. of concentrated sulphuric acid slowly run in. The temperature is then allowed to rise to 15° or 20° C., and after stirring for thirty minutes, the whole is poured into 1500 c.e. of water. The nitro-oxalyl compound separates, and the oxalyl residue is split off by boiling the mixture for one hour. The yield is about 86 per cent. (3) Instead of nitrating the oxalyl derivative as above, the urethane derivative may be used. (4) o-Nitroaniline and arsenie acid are heated at 200° to 210° C. for ten minutes and the melt extracted with 10 per cent, sodium hydroxide solution, from which extract the arsinic acid is precipitated by acid. In this preparation bis- 3-nitro-4 -aminophenyl)-arsinic add results in small yield as a by-product. 

When these approaches proved unsuccessful, a total synthesis of erysotrine was finally achieved beginning with the oxalyl derivative (LIT) of 4-methoxycyclohexanone. The synthetic scheme has so far been reported only in preliminary communications 27, 36). The condensation with -(3,4-dimethoxyphenyl)-ethylamine leading to the tetracyclic erythrinane skeleton and the further conversion to LV have been discussed in Section III, C (Fig. 8) the remainder of the synthesis is outlined in Fig. 10. 

The group of antitumour agents related to pederin have a common structural feature 96 of a functionalised tetrahydropyran attached through an amide linkage to a variety of complex amines. In his successful syntheses of these compounds, Kocienski21 chose to disconnect next to the ring and use a reagent 99 for the d1 synthon 97 that would be acylated by the oxalyl derivative 98. 

The di- or tri-thiocarbonate (74.8) is cyclized by first treating it with allyloxalyl chloride to give the IV-oxalyl derivative which is not isolated in a pure state but is warmed with triethyl phosphite at 40-85 °C to give the ring system of isocephem (or iso-oxacephem) antibiotics which are synthesized by a broadly similar route. 

The 2, 19-epoxydienone (372) has been prepared by the action of acid or base upon either the fluoro- or chloro-19-acetates (371), which were obtained by halogenation of the oxalyl derivative of (370) and subsequent cleavage of the 6/5,19-oxide ring with acetic anhydride-toluene-p-sulphonic acid. 

In the case of 2-methyl-4-phenyldiazepine, the 2-oxalyl derivative could also be obtained under different conditions.44 Halogen atoms substituted on 2(4)-methyl groups readily undergo nucleophilic substitution thus 2,4-bis(bromomethyl)benzodiazepine gives the 2,4-bis(iodomethyl) analog with sodium iodide in acetone.11... 

Treatment of oxalyl chloride with concentrated hydrogen peroxide under base catalysis in the presence of fluorescers leads to bright chemiluminescence.28 This rather unusual observation was also demonstrated for other oxalyl derivatives (9)29 and interpreted3 to involve 1,2-dioxetandione (3) as the intermediate [Eq. (7)]. Although isolation of the carbon dioxide dimer (3) was claimed,4 no characteristic spectral data could be observed.16 Furthermore, the claim30 of detecting... 

Source of Other Oxalyl Derivatives. A variety of other oxalyl derivatives is known—oxalyl diimidazole can serve as an... 

S. A-G occur in the leaves and fruits of Cassia species (C. senna, C. angustifolia, Fabaceae) and in rhubarb roots, sometimes as oxalyl derivatives (senno-sides E, F). S. are mostly formed from the corresponding anthrone glycosides when the senna leaves are dried. Drugs containing S. are used in therapy for acute constipation (see table, p. 581). 

Believed to proceed entirely via intramolecular or chloride-induced decarbonjdation of oxalyl derivatives, (CFgY)(CFjX)C N-CO-COCl, since the imine-hydrogen chloride addocts (CF,),CC1-NH, and (CF 0(CFjCl) CCl NHa do not react with oxalyl chloride under the conditions used to procure (CT,Y)(CFaZ)CCl-NCO. ... 

Anisomyces odoratus has been reported to produce odoriferous simple aromatic compounds, terpenes and lanostadienoic acids (22). The unusual amino acid 2-amino-4-N-ureidopropionic acid and its oxalyl derivative were recently isolated from Coniophora puteana (23). 

Evans, C.S., P.J. Burns, M. Dutton, S.Brown 2-Amino-4-N-ureidopropionic acid (albizzine) and its oxalyl derivative in hyphae of Coniophora puteana. Phytochem. 29, 2159 (1990). 

As an example of the first type, tryptophan (6) is converted to 5-hydroxy-L-tryptophan (7), which occurs in plants as its acetyl, 4-glutamyl, and oxalyl derivatives (Fig. 13.2). 

N -Oxalyl-L-2,3-diaminopropionic acid (57) is derived from 2,3-diaminopropionic acid (69), which, in turn, is derived from asparagine (64) (Fig. 13.13), The oxalyl derivative (57) is a potent neurotoxin found in Lathyrus sativus and certain other legumes. The corresponding. /V -methyl derivative occurs in certain cycads such as Cycas drdnalis (Rosenthal, 1991). 

L-2,4-Diaminobutyric (L-a,7-diaminobutyric) acid (56) is derived from 3-cyanoalanine (58). This compound also is found in a number of Lathyrus spedes. The corresponding oxalyl derivative (65) co-occurs with L-2,4-diaminobutyric acid (Rosenthal, 1982). 

Consumption of seeds of the genus Lathyrus (Fabaceae) by man and his domestic animals produces a syndrome called lathyrism. Different amino acids produce the two forms of this malady neurolathyrism and osteolathyrism. 3-Aminopropionitrile 0-aminopropionitrile) (59) is the active osteolathyritic factor in Lathyrus species. Several factors are responsible for neurolathyrism. 3-Cyanoalanine (58), its 4-glutamyl derivative, 2,4-diaminobutyric acid (56), and the N-oxalyl derivative of 2,3-diaminopropionic (a,3-diamino-propionic) acid (57) are all known to be involved. These compounds are found primarily in plants of the genus iMth-yrus. 3-Cyanoalanine (58) and its 4-glutamyl derivative are also common in Vida species. Several related series of compounds are found in other members of the Fabaceae. 

After the research of Wohler and Liebig (1838, see p. 333), uric acid and its derivatives were investigated by Schlieper. The latter showed that uric acid on reduction by hydriodic acid forms glycocoll and the decomposition products of urea (NH3 and CO2). Gerhardt formulated alloxan as the mesoxalyl, and parabanic acid as the oxalyl, derivatives of urea, which he then regarded as hydrate d oxyde de cyanammonium , giving complicated formulae, which were simplified by Kekule as ... 

Oxalic acid and calcium oxalate, a store for excess Ca + (E 2.2) and a repellent for potential predators (E 5.5.3), accumulate frequently in plants and microbial cultures. Oxalyl derivatives of amino acids occur in different groups of organisms (D 9.1). O-Oxalyl-L-homoserine is involved in the biosynthesis of L-methio-nine in microorganism (D 12). 

Nonprotein amino acids are usually found in the free state or as part of simple products such as y-glutamyl, acetyl or oxalyl derivatives. They also occur, however, as constituents of small peptides, such as the phalloidins and amanitins (D 23), or as precursors of other secondary products (see formation of glucosinolates, D 9.4). 

Oxalyl deriv. cryst. from EtOH. M.p. 92-3°. WS-f 48-24°inC8Hg. 

Phosgene reacts with oximes to form 0-(ch oroformyl) oximes 124, which, on addition of antimony pentachloride, undergo smooth Beckmann rearrangement with loss of carbon dioxide to give the nitrilium salts 125 almost quantitatively [66]. With oxygen or nitrogen nucleophiles, O-(chloroformyl) oximes 124 form symmetrical and unsymmetrical oxalyl derivatives. 

The aspartic acid semi-nitrile formed initially can be decarboxylated to P-amino propionitrile which, just as its y-glutamyl derivative, is responsible for osteolathyrism in animals. Hydrolysis of the semi-nitrile yields aspartic acid, hydrolysis and reduction yield 2,4- diaminobu-tyric acid, the oxalyl derivative of which, hke oxalyldiaminopropionic acid, is a human neurotoxin. The main symptoms of neurolathyrism are paralysis of the hmbs and muscular rigidity. 

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