Monocarboxylations

By increasing the molar proportion of the monocarboxylic acid, the yield of (II) is improved. Thus electrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIH) and sebacic acid (IX) ... 

Hydrogenolysis of the diallyl alkylmalonate 757 with formic acid in boiling dioxane affords the monocarboxylic acid 758. Allyl ethyl malonates are converted into ethyl carboxylates[471]. The malonic allyl ester TV-allylimide 759 undergoes smooth deallylation in refluxing dioxane to give the simple imide 760(472]. The allyl cyanoacetate 761 undergoes smooth decarboxylation to give... 

Probably first obtained by Hantzsch and Arapides (105) by condensation of a,/3-dichlorether with barium thiocyanate, and identified by its pyridine-like odor, thiazole was first prepared in 1889 by G. Popp (104) with a yield of 10% by the reduction in boiling ethanol of thiazol-2-yldiazonium sulfate resulting from the diazotization of 2-aminothiazole. prepared the year before by Traumann (103). The unique cyclization reaction affording directly the thiazole molecule was described in 1914 by Gabriel and Bachstez (106). They applied the method of cyclization, developed by Gabriel (107, 108), to the diethylacetal of 2-formylamino-ethanal and obtained thiazole with a yield of 62% - Thiazole was also formed in the course of a study on the ease of decarboxylation of the three possible monocarboxylic acids derived from it (109). On the other... 

Esters of nonenolizable monocarboxylic acids such as ethyl benzoate give p diketones on reaction with ketone enolates... 

Acid Anhydrides. Symmetrical anhydrides of monocarboxylic acids, when unsubstituted, are named by replacing the word acid by anhydride. Anhydrides of substituted monocarboxylic acids, if symmetrically substituted, are named by prefixing bis- to the name of the acid and replacing the word acid by anhydride. Mixed anhydrides are named by giving in alphabetical order the first part of the names of the two acids followed by the word anhydride, e.g., acetic propionic anhydride or acetic propanoic anhydride. Cyclic anhydrides of polycarboxylic acids, although possessing a... 

Aluminum salts of carboxylic acids, aluminum carboxylates, may occur as aluminum tricarboxylates (normal aluminum carboxylates), Al(OOCR)2 monohydroxy (monobasic) aluminum dicarboxylates, (RCOO)2Al(OH) and dihydroxy (dibasic) aluminum monocarboxylates, RCOOAl(OH)2. Aluminum carboxylates are used in three general areas textiles, gelling, and pharmaceuticals. Derivatives of low molecular weight carboxyUc acids have been mainly associated with textile appHcations those of fatty carboxyUc acids are associated with gelling salts and more complex carboxylates find appHcations in pharmaceuticals. 

This group of aluminum carboxylates is characterized mainly by its abiUty to gel vegetable oils and hydrocarbons. Again, monocarboxylate, dicarboxylate, and tricarboxylate salts are important. The chemical, physical, and biological properties of the various types of aluminum stearates have been reviewed (29). Other products include aluminum palmitate and aluminum 2-ethylhexanoate (30). 

Carboxylates, Oxalates, and Catecholates. Complexes of Th(IV) with mono-, di-, tri-, and polycarboxylates have been extensively studied. Monocarboxylates, RCOO , have been complexed with Th(IV), eg, Th(RCOO)4, where R = H, CH, CCl, or and M Th(HC02)4, ... 

The present method for preparing aromatic dicarboxylic acids has been used to convert phthalic or isophthalic acid to tereph-thalic acid (90-95%) 2,2 -biphenyldicarboxylic acid to 4,4 -biphenyldicarboxylic acid 3,4-pyrroledicarboxylic acid to 2,5-pyr-roledicarboxylic acid and 2,3-pyridinedicarboxylic acid to 2,5-pyridinedicarboxylic acid. A closely related method for preparing aromatic dicarboxylic acids is the thermal disproportionation of the potassium salt of an aromatic monocarboxylic acid to an equimolar mixture of the corresponding aromatic hydrocarbon and the dipotassium salt of an aromatic dicarboxylic acid. The disproportionation method has been used to convert benzoic acid to terephthalic acid (90-95%) pyridine-carboxylic acids to 2,5-pyridinedicarboxylic acid (30-50%) 2-furoic acid to 2,5-furandicarboxylic acid 2-thiophenecar-boxylic acid to 2,5-thiophenedicarboxylic acid and 2-quinoline-carboxylic acid to 2,4-quinolinedicarboxylic acid. One or the other of these two methods is often the best way to make otherwise inaccessible aromatic dicarboxylic acids. The two methods were recently reviewed. ... 

In this method, an oligoethylene glycol is treated with 0.3 eq. of sodium bromoace-tate in methanol. The resulting monocarboxylic acid salt is then treated with toluene-sulfonyl chloride, sodium carbonate and dioxane. After heating the reaction mixture at 50° for an hour, the product was obtained either by Kugelrohr distillation or extraction. The two compounds produced in the reaction below (i.e., n = 1 and n = 2) were formed in 38% and 42% yields respectively . 

Dicarboxylic acids react more sensitively than do monocarboxylic acids. Fatty acids and amino acids cannot be detected. 

Constitution of Yohimbine and its Isomerides. The yohimb alkaloids are methyl esters of acids. Yohimbine, yohimbene, mesoyohimbine (isoyohimbine) and y-yohimbine (table, p. 502) are hydrolysed to four, distinct, monocarboxylic acids, C2,yH2402N2, each of which on decarboxylation by heating with soda-lime yields yohimbol, long supposed to be a secondary alcohol, Ci,yH240N2, but which Witkop has shown to be a ketone and has re-named yohimbone, C18H22ON2, m.p. 307° (dec.),... 

Mono-carbonsaure, /. monocarboxylic acid, -chloressigsaure, /. monochloroacetic acid, -chlorhydrat, n. monohydrochloride. 

Symmetrical anhydrides of unsubslituted monocarboxylic acids and cyclic anhydrides of dicarboxylic acids are named by replacing the word acid with anhydride. 

Finally, if only the -CH2OH end of the aldose is oxidized without affecting the -CHO group, the product is a monocarboxylic acid called a uronic acid. The reaction must be done enzymatically no satisfactory chemical reagent is known that can accomplish this selective oxidation in the laboratory. 

Aldonic acid (Section 25.6) The monocarboxylic acid resulting from mild oxidation of the -CHO group of an aldose. 

Dichloromethyl methyl ether may be employed preparatively in various ways. Thus it effects the replacement of carbonyl and hydroxyl oxygens by chlorine,11 and may be used in the preparation of a-acetochlorosugars 12 and acid chlorides, particularly those derived from acetylated monocarboxylic acid sugars 12 13... 

COOH simple monocarboxylic acids do not react, but dicarboxylic acids in which the carboxyl groups are conjugated with each other do ... 

GC separation of derivatized carboxylic acids, 46-52 bacterial fatty acids, 51-52 bile acids, 50-51 C6-C24 monocarboxylic acids and dicarboxylic acids, 51 cyano acids, 52 higher-boiling acids, 49 itaconic acid, citraconic acid, and mesaconic acid, 49... 

Chrysanthemum dicarboxylic acid or pyrethric acid may exist in eight stereoisomers, owing to the trans or cis configuration on the side chain of the double bond as well as that of the cyclopropane. The natural acid has been shown to be the trans-trans acid. As in the case of the chrysanthemum monocarboxylic acid, the naturally occurring configuration is more insecticidally active than the racemic form or any of the three isomers synthesized. 

Cyclethrin, 3-(2-cyclopentanyl)-2-methyl-4-oxo-2-cyclopen-tenyl chrysanthemum monocarboxylate... 

This is interesting when one considers the effect of synergists on the synthetics. All of the synthetics mentioned above are based on chrysanthemum monocarboxylic acid and in the case of allethrin, cyclethrin, and furethrin on the alcohol moiety there is only one double bond. When checked against the standard synergists, these synthetics do not show the degree of synergism shown by pyrethrins and this may be because of the fact that there is only one double bond for epoxidation, compared with two in the pyrethrolone radical, and therefore the synergist would not block this epoxidation step as effectively. 

METHYL CHRYSANTHEMATE DIMETHYL PYRETHRATE mixture contribute to the total monocarboxylic and dicarboxylic acids found. 

It was recently found that the free monocarboxylic and dicarboxylic acids derived from pyrethrum hydrolysis will pass through the gas chromatograph and present suitable responses. When this is followed up, it is expected that the method will be simplified and provided better over-all recoveries. 

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