Acid anhydrides with amino acids

The analgesic and anti-inflammatory Indoprofene (42) can be made by several routes, two of which involve cyclisations. Treatment of phthalic anhydride with amino acid (43) gives imide (45) in one step - the cyclisatlon of (44) must be faster than the inter-molecular reaction by which it is formed. Reduction of (45) give.s Indoprofene as the reactive imide is easily reduced as far as the unreactive amide. 

In order to eliminate the influence of temperature on the rate of a chemical reaction, a reaction mixture of phthalic anhydride with amino acids was placed in a block of ice and then irradiated under microwave conditions. Ice was used to cool the reaction mixture because opposite to water it is transparent to microwaves (e 3.2, c" 0.0029 at 25°C for 2.45 GHz) [26]. The reaction product was formed after 3 min. of irradiation while under conventional conditions the reaction was conducted in a boiling toluene solution for 1.5 h. However, since in such a case microwaves interact directly with the reaction mixture and temperature was not monitored during the experiments, it was stated that the increase of the reaction rate is not only due to thermal effects [27]. 

The palladium(O) catalysed tandem cyclisation of a bromoallene tethered with a sulfamide group 124 gives bicyclic azepines 125. The analogous reaction with Af-tethered bromoallene sulfamide 126 afforded bicyclic diazepine 127 <07CEJ1692>. Condensation of thiaisatoic anhydride with -amino acids proved to be a straightforward method for the synthesis of thieno[3,2-< ][l,4]diazcpin-2,5-dionc analogues 128 <07JOC2662>. 

The reaction of pyromellitic dianhydride or benzophenone-3,3, 4,4 -tetra-carboxylic anhydride with amino acids or lactams followed by condensation of the resulting diacids with diacetates of hydoquinone, 2,6-dihydroxynaph-thalene or 4,4 -dihydroxybiphenyl produced layer polymers (42). With the exception of the polymer with y=ll, all the polymers based on Ar = 4,4 -biphenylyl exhibit a smectic mesophase. The polymer with y = 10 and Ar = 1,4-phenylene exhibits a smectic mesophase. Polymers based on Ar = 1,4-phenylene or 2,6-naphthalene melt directly into an isotropic phase. 

The reaction is freely reversible and the enzyme catalyzing it has been called DPN pyrophos-phorylase. This transfer of one 5 -nucleotide to another produces a pyrophosphate bond between them. The reaction is the prototype of a large number of such nucleotidyl transfers to other phosphate compounds. These include transfers to various sugar phosphates to form the nucleoside diphosphate sugar coenzymes, to choline phosphate to form C3fiidine diphosphate choline, and to phosphatidic acid to form cytidine diphosphate diglyceride. This nucleotidyl transfer is the protot)q)e also for transfers of nucleotides to produce mixed acid anhydrides with fatty acids, amino acids, and sulfates. In each instance inorganic pyrophosphate is produced this is also true of the nucleotidyl transfers which produce RNA and DNA. 

Hydrolysis of the azlactone leads to the acylaminooinnamic acid the latter may be be reduced catal3rtlcally (Adams PtOj catalyst 40 lb. p.s.i.) and then hydrolysed by hydrochloric acid to the amino acid. Alternatively, the azlactone (say, of a-benzylaminocinnamic acid) may undergo reduction and cleavage with phosphorus, hydriodic acid and acetic anhydride directly to the a-amino acid (d/ p phenylalanine). 

C15H21NO5) see Gusperimus trihydrochloride 4-[hydroxy[5-[[(phenylmethoxy)carhonyl]amino]pen-tyl]amino]-4-oxobutanoic acid (C,7H24N20ft 106410-46-2) see Deferoxamine D-a-(4-hydroxyphenyl)-tx-(2-methoxycarbonyl-l-methyl-cthenylamino)acetic acid anhydride with monoethyl carbonate... 

Carboxylic acids (8.54) are frequently conjugated with amino acids, especially glycine (Scheme 8.18). The carboxylic acid is first activated as a mixed anhydride (8.55). Reaction of the anhydride with the thiol of coenzyme A forms an intermediate (8.56) that reacts with the amine of an amino acid. The new conjugate (8.57) has increased water solubility to improve elimination. 

Since the dye is patented, it is probable that it is represented by one of the five examples in the patent. The most likely possibility is example 3, the condensation product from 4-amino-l,8-naphthalic acid anhydride with cyclohexylamine, or example 4, the sulfonation product of this compound. 

The acid reduces ammoniacal. silver nitrate solution, and with sodium nitrite gives a yellow diazo-compound, which couples with resorcinol to give a bluish-red dye. Wren dissolved in sodium hydroxide and treated with acetic anhydride, the amino-acid yields an acetyl derivative, which separates in colourless prisms from water, and yields amorphous calcium and magnesium salts. ... 

Carbodiimides, in particular dicyclohexylcarbodiimide, have been applied in many syntheses where dehydration had to be performed under mild conditions. It is therefore no surprise that this reagent was also introduced for the synthesis of acid anhydrides from carboxylic acids." " In order to avoid N-acylation the reactions are carried out at low temperature. First 0-acylisoureas are formed, which then react further with free acid to the acid anhydride (equation 34). The reaction has been exploited in particular for the preparation of peptides." )V-alkoxycarbonyl-protected amino acids can be transformed in high yield to the corresponding anhydrides, which themselves are activated acid derivatives and may be converted to peptides. As in many other examples polymer-bound carbodiimides may prove superior sometimes, as the isolation of the products is facilitated. Easy preparation of acid anhydrides is possible in this way." ... 

Maleic and phthalic anhydrides condense with amino acids under MW to afford the desired products in excellent yields [Eq. (78)] ... 

The reagent promotes the coupling in high yields of acylamino acids with amino acid esters in benzene, ethanol, or THF at room temperature. No racemization was detected in the supersensitive Young test, and Bz-Leu-Gly-OEt, an 33.5°, was synthesized in 95% yield. Activation of the carboxyl group involves the transient formation of a mixed carbonic anhydride.3... 

AMINO ETHYL-1,2-ETHANEDIAMINE,1,4,7,10,13-PENTAAZATRIDECANE-3-AMINOPHENYLMETHANE (108-44-1) Combustible liquid (flash point 188°F/87°C). Light causes slow decomposition. Violent reaction with strong oxidizers, including red fuming nitric acid. Incompatible with strong acids, acid chlorides, acid anhydrides, organic anhydrides, isocyanates, aldehydes, oxidizers. Attacks some plastics, rubber, and coatings. 

Isostrychninic acid, like strychninic acid, is an amino acid which gives a crystalline A -nitroso derivative and couples with various diazonium salts with the formation of colored azo compounds (177). Regeneration of isostrychnine results from dehydration of the acid with acetic anhydride or benzoyl chloride (241). 

For the production of glycinamide ribonucleotide, an acyl phosphate (anhydride) intermediate is formed by reaction of ATP -with a carboxylic acid of an amino acid (glycine), whereas in the production of guanylate (GMP) a phosphoryl ester intermediate is formed by reaction of ATP with an enol alcohol on the purine ring of the nucleotide. 

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