CARBOXYLIC ACID DIACETATE

CA Index Name Spiro[isobenzofuran-l(3//),9 -[9//] xanthene]-5-carboxylic acid, 3, 6 -bis(acetyloxy)-2, 7 -difluoro-3-oxo- 

Other Names Oregon Green 488 carboxylic acid diacetate 

Chemical/Dye Class Xanthene Molecular Formula C25H14F2O9 Molecular Weight 496.37 

Physical Form Colorless crystals Off-white solid Solubility Insoluble in water soluble in dimethyl 

Industrial Applications Not reported Safety/Toxicity No data available 

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OREGON GREEN 488 CARBOXYLIC ACID DIACETATE Other Names Oregon Green 488 carboxylic acid diacetate... 

Nitroamlines. Acetyl derivatives (p. 388), Benzoyl derivatives (p. 388). Diamines. Diacet> l derivatives (p. 388), Dibenzoyl derivatives (p. 388). Halogeno-hydrocarbons, a-Naphthyl ethers (from reactive halogen compounds, p. 391, and their Picratcs, p. 394), Nitro-derivatives (p.39i). Carboxylic acid (if oxidisable side chain) (p. 393). 

Trihydroxy-21-diazopregnan-20-one 3,19-diacetate, 176 3 a,20,23 -Trihydroxy-16a-methyl-17(20)-oxido-11-0X0-2l-norchol-22-enoic acid 24(20)-lactone 3,23,diacetate, 191 3a,l l, 20 -Trihydroxy-5/3-C-norpregnane-l l -carboxylic acid, 438 3/3,11 a ,20/3-Trihydroxy-5o -pregnan-18-oic acid 18,20-lactone-3,l 1-diacetate, 252 3/3,5/S, 19-Trihydroxypregnan-20-one 3,19-diacetate, 176... 

Trimethyltin chloride reacts with carboxylic acids at 100° to give the corresponding chloride carboxylates Me2Sn(Cl)OCOR (187, 188), and diethyltin dihydride, triethyltin hydride, hexaethylditin, and bis(triethyltin) oxide have been shown to react with lead tetraacetate to give diethyltin diacetate or triethyltin acetate, as appropriate (189). 

A hydroxymethyl group can be introduced (ArH —> ArCH20H) by several variations of this method. Alkylation of these substrates can also be accomplished by generating the alkyl radicals in other ways from hydroperoxides and FeS04, from alkyl iodides and H2O2—Fe V from carboxylic acids and lead tetraacetate, or from the photochemically induced decarboxylation of carboxylic acids by iodoso-benzene diacetate. 

Buten-4-carboxylic acid, p51 cw-2-Butenedioic acid, ml 2-Butene-l,l-diol diacetate, d28 ra s,-2-Buten-l-ol, c311... 

For both reactions a RhCl3/CH3l/TPO catalyst in acetic acid as reaction solvent affords propionic acid in more than 80 % yield according to the respective stoichiometries of Equations 12 and 13. Although acetic acid is present in excess in the reaction medium, it does not participate in the homologation as reactant. Only traces of propionic acid are produced in the absence of methyl acetate, ethyli-dene diacetate or acetic anhydride under our reaction conditions. Homologation of carboxylic acids has been reported by Knifton (10) to require more severe reaction conditions (220 °C, > 100 bar). 

The methyl substituent of 2-methyl-4,8-dihydrobenzo[l,2- 5,4-. ]dithiophene-4,8-dione 118 undergoes a number of synthetic transformations (Scheme 8), and is therefore a key intermediate for the preparation of a range of anthraquinone derivatives <1999BMC1025>. Thus, oxidation of 118 with chromium trioxide in acetic anhydride at low temperatures affords the diacetate intermediate 119 which is hydrolyzed with dilute sulfuric acid to yield the aldehyde 120. Direct oxidation of 118 to the carboxylic acid 121 proceeded in very low yield however, it can be produced efficiently by oxidation of aldehyde 120 using silver nitrate in dioxane. Reduction of aldehyde 120 with sodium borohydride in methanol gives a 90% yield of 2-hydroxymethyl derivative 122 which reacts with acetyl chloride or thionyl chloride to produce the 2-acetoxymethyl- and 2-chloromethyl-4,8-dihydrobenzo[l,2-A5,4-3 ]-dithiophene-4,8-diones 123 and 124, respectively. 

Catalysts Catalysts are widely used for PU manufacture. Sometimes a combination of two or three catalysts is required to obtain the desired balance of reaction rates between compounds of differing active hydrogen activity. Metal compounds, especially organotin compounds, are much more efficient catalysts than tertiary amines for the -OH/NCO reaction. In addition to more commonly used dibutyltin(IV) dilaurate, dibutyltin(IV) diacetate, dialkyltin(IV) oxide or salts of divalent fin with a variety of carboxylic acids such as stannous octoate, hexoate and naphthenate etc. are available for this purpose. Combination of tin catalysts with tertiary amines has been reported to lead to a synergistic increase in catalytic activity. 

Furans can be nitrated with a mixture of fuming nitric acid and acetic anhydride at low temperature. The initial products from the nitration of furan-2-carbaldehyde and its diacetate are (525), (526), (527) and (528), indicating that both 1,4- and 1,2-addition to the diene system may occur (76KGS601) (see Section 3.11.2.2.3). Analogous products are obtained from the nitration of furan-2-carboxylate (75KGS883). Carboxylic acid groups are often replaced thus 5-bromofuran-2-carboxylic acid on nitration yields 5-bromo-2-nitrofuran, which may be readily converted to 5-iodo-2-nitrofuran and 2,5-dinitrofuran (61ZOB263). 

Iodosobenzene diacetate [IBD, PhI(OAc)2] is able to oxidize benzylic alcohols to benzaldehydes when a solid mixture of iodosobenzene diacetate and the alcohol is irradiated with microwaves. Best results are obtained when iodosobenzene diacetate is supported on alumina.118 The use of polymer supported iodosobenzene diacetate (PSDIB) simplifies the work-up in the oxidation of benzylic alcohols to benzaldehydes.119 PSDIB can be employed in the presence of KBr and using water as solvent, resulting in the transformation of secondary alcohols into ketones and primary alcohols into carboxylic acids.117... 

Alkaloids of Delphinium dictyocarpum DC.—Dictysine [C21H33N03 m.pt 184—186°C] has been assigned structure (37) on the basis of chemical and spectroscopic studies.25" An unpublished X-ray analysis256 demonstrates that (37) is incorrect and that the structure should be as shown in (37a). Derivatives of dictysine (38)—(42) are shown here as the corrected structures. This alkaloid was isolated from the epigeal parts of Delphinium dictyocarpum DC.26 On acetylation of dictysine with acetyl chloride, the triacetate (38) and the two diacetates, (39) and (40), were obtained. The reaction of dictysine with one molar equivalent of periodic acid for three hours gave the a-hydroxy-ketone (41), while treatment with excess periodic acid for three days yielded the aldehyde carboxylic acid (42). These structures were supported by mass-spectral, i.r., and XH and 13C n.m.r. analyses. This is the first example of a C20 diterpenoid alkaloid which contains hydroxyl groups at C-16 and C-17. 

Several other processes have been developed, however, to accomplish the oxidative decarboxylation of carboxylic acids oxidation by Pb(OAc)4, by iodosobenzene-diacetate, and by Ag(II) salt generated in situ in a catalytic cycle from a variety of peroxides (benzoyl peroxide, percarbonate, perborate) [2] other than the already mentioned peroxydisulfate. Representative examples are shown in Eqs (9)—(12) of Table 2. 

Diphenyl tellurium diacetate exchanged acetate for other acyloxy groups when treated with an excess of the carboxylic acid in chloroform at 20° for 30 min4. 

When selenophene-2-aldehyde or its diacetate is sulfonated with dioxane-sulfur trioxide, 5-sulfoselenophene-2-aldehyde is formed. The 2-carboxylic acid with oleum gives 5-sulfoselenophene-2-car-boxylic acid containing an admixture ( 20%) of the 4-sulfo isomer. The sulfo group is readily replaced by nitro by the action of fuming nitric acid.51... 

The behaviour in solution of dimethyltin(IV) complexes containing different aminopoly-carboxylic acids were also investigated . The X-ray crystal structure analyses of the tin complexes with Af-methyliminodiacetate (mida), pyridine-2,6-dicarboxylate (pdc) and ethylenediamine-Al,Af -diacetate (edda) revealed dimeric structures for the first two compounds and a monomeric structure for the complex dimethyltin (edda). In contrast, the dimethyltin(IV) complex (137) with ethylenediamine-Af,Af,Af, Af -tetraacetate (edta) and water is a polymer in which each tin atom adopts a distorted pentagonal-bipyramidal configuration with the two methyl groups in axial positions. 

The oxidative decarboxylation of aliphatic carboxylic acids is best achieved by treatment of the acid with LTA in benzene, in the presence of a catalytic amount of copper(II) acetate. The latter serves to trap the radical intermediate and so bring about elimination, possibly through a six-membered transition state. Primary carboxylic acids lead to terminal alkenes, indicating that carbocations are probably not involved. The reaction has been reviewed. The synthesis of an optically pure derivative of L-vinylglycine from L-aspartic acid (equation 14) is illustrative. The same transformation has also been effected with sodium persulfate and catalytic quantities of silver nitrate and copper(II) sulfate, and with the combination of iodosylbenzene diacetate and copper(II) acetate. ... 

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