Itaconic anhydride

Ethanediol y-(p-methoxyphenyl)itaconic anhydride r = 1 (2 d-step of esterification) No 160-200... 

Itaconyl chloride has been prepared previously only by the reaction of itaconic anhydride with phosphorus pentachloride.4... 

The norbornene derivative 16, obtained exclusively as the exo adduct via a Diels-Alder reaction of itaconic anhydride with cyclopentadiene followed by hydrolysis and esterification [7], was found to be a suitable precursor for an enolate of type 14 (Scheme 2). Due to the quaternary center at C-3 eno-lization with base proceeded unambiguously, giving rise to a diastereomeric mixture of lactones 17/18 after reaction with hexanal. Retro-Diels-Alder reaction led to the monocyclic lactones 19/20 (2 1), elegantly unmasking the cxo-methylene group found in so many paraconic acids [8]. Hydrolysis of this mixture in refluxing butanone with 6 N HCl [9] effected epimerization... 

The structure of the pyridazine-based antidepressant agent minaprine (34-6) departs markedly from both the older tricyclic drugs and the more recent selective serotonin re-uptake inhibitors. There is evidence that the compound acts via a dopa-mimetic route. Friedel-Crafts acylation of benzene with itaconic anhydride (34-1) leads to the keto-acid (34-2). Condensation with hydrazine leads to the formation of the hydrazine and hydrazide bonds the double bond shifts into the ring to give the fully unsaturated pyridazinone (34-3) this is then converted to the chloride (34-4) in the usual way. The displacement of halogen by the amine on 3-(A -morpho-lino)propylamine (34-5) affords (34-6) [36]. 

A stirred solution of itaconic anhydride (71.8 mmol) dissolved in 70 ml CHC13 at 0°C was treated with the dropwise addition of 3-aminopropyl terminated poly(dimethyl-siloxy)silane (Mn 1000 Da 32.36 g) dissolved in 35 ml CHC13 over 1 hour. After an additional hour of stirring at 0°C, the cooling bath was removed, the solution warmed to ambient temperature, and stirred an additional 1 hour. The product was isolated after the solution was concentrated. 

Itaconic anhydride (2-propen-l,2-dicarboxylic anhydride) [2170-03-8] M 112.1, m 66-68°, 67-68°, 68°, b 139-140°/30mm. Crystd from CHCl3/pet ether. Can be distd under reduced press. Distn at atm press, or prolonged distn causes rearrangement to citraconic anhydride (2-methylmaleic anhydride). If the material (as seen in the IR spectrum) contains much free acid then heat with acetyl chloride or SOCI2, evaporate... 

A. Citraconic Anhydride Two hundred and fifty grams of itaconic anhydride (Note r) is distilled rapidly at atmospheric pressure in a 500-cc. modified Claisen flask with a 15-cm. (6-in.) fractionating column (Note 2). The receivers for the distillate must be changed without interrupting the distillation. The distillate passing over below 200° consists of water and other decomposition products. The fraction which distils at 200-2150 consists of citraconic anhydride and is collected separately. The yield is 170-180 g. (68-72 per cent of the theoretical amount) of a product melting at 5.5-6°. On redistillation under reduced pressure there is obtained a yield of 155-165 g. (62-66 per cent of the theoretical amount based on the itaconic anhydride used) of a product which boils at io5-iio°/22 mm. and melts at 7-8° (Note 3). 

The crude itaconic anhydride obtained as described on page 70 was used. Itaconic acid may be substituted for the anhydride. 

A. Itaconic Anhydride A 500-cc. Pyrex Kjeldahl flask is fitted with an outlet tube 12 mm. in diameter bent for downward distillation. It is attached to a 100-cm. water-cooled condenser having an indented Pyrex inner tube (Note 1). Two 250-cc. long-neck distilling flasks are used in series as receivers, the vapors being led to the center of each flask by means of an adapter and glass tubing. Both receivers are cooled in a mixture of ice and water. 

Two hundred grams of citric acid (0.95 mole) (Note 2) is placed in the reaction flask (Note 3) and heated with a free flame until melted. Then the flask is heated very rapidly with a large Meker burner, and the distillation is completed as rapidly as possible (ten to twelve minutes). Care must be taken to avoid superheating (Note 4). The distillate consists of water and itaconic anhydride, most of which distils at 175-190°. The distillate is immediately (Note 5) poured into a separatory... 

B. Itaconic Acid Forty grams of itaconic anhydride is refluxed with too cc. of water for one hour. The flask is then set aside to cool, and finally placed in an ice bath. The acid crystallizes and is filtered and dried. The yield is 11-18 g. (24-39 Per cent °f the theoretical amount) of a product which melts at 162-165°. On concentrating the mother liquor to one-third of the original volume, an additional amount of lower-melting product may be obtained (Note 8). 

The purity of the itaconic anhydride seems to vary greatly with the conditions of the experiment. The crude anhydride always deposits crystals of itaconic acid on standing, probably due to water dissolved or suspended in the anhydride. Some idea of the purity can be obtained by the quantity of itaconic acid that is obtained from it. If the distillation proceeds at exactly the right rate, the anhydride is pure and melts at 67-68°. 

In some cases no itaconic acid crystallizes. This apparently happens when the distillation of the citric acid has not been carried out rapidly enough and the itaconic anhydride contains a large amount of citraconic anhydride. 

Itaconic anhydride has been made by heating itaconic acid and by distillation of citric acid.1... 

Itaconic acid Itaconic anhydride Artificial glass, resins fibres, lattices, detergents, bioactive compounds Willke and Vorlop, 2001 Reddy and Singh, 2002 Fevinson etal., 2006... 

Methyl acrylate Itaconic anhydride FN JV-Carboethoxy maleimide MAn... 

Magnesium perchlorate has been used as a catalyst for the synthesis of benzothiazepines 153 from chalcones and 2-aminothiophenol <07JHC541> while derivatives 154 using 3-cinnamoyl coumarin as the a,p-unsaturated ketone have also been synthesised <07JHC145>. The reaction of 2-aminothiophenol with itaconic anhydride also gives the benzothiazepine system 155 <07JHC457> while dibenzothiazepines 157 were formed by denitrocyclisation of the sulfide 156 <07JHC1247>. 

Construction of one biphenyl-based metaloproteinase inhibitor starts with the Friedel-Crafts acylation of 4-chlorobiphenyl (31) with itaconic anhydride... 

Itaconic acid (I), which is produced commercially by fermentation, is isomeric with mesaconic acid (II) and dtraconic acid (III), and in the presence of strong base may form equilibrimn mixtures of the salts (4). Other derivatives such as the esters and the amides can be similarly isomerized (5, 6). The mesaconate seems to be the most stable isomer in polar solvents in the temperature range — 78° to 100° C or higher. The well known conversion of itaconic to citraconic add by heating above the melting point probably jjroceeds throu itaconic anhydride. 

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