Succinic condensation

When cinnamaldehyde, succinic acid and acetic anhydride are heated in the presence of litharge (PbO), the aldehyde and the succinic acid condense to give the dicarboxylic acid (I), which undergoes decarboxylation to give the pale yellow crystalline 1,8-diphenyloctatetrene (II), Kuhn has shown that as the... 

Method A. In a 500 ml. round-bottomed flask, fitted with a reflux condenser attached to a gas trap (Fig. II, 13, 8), place 59 g. of succinic acid and 117-5 g. (107-5 ml.) of redistilled acetyl chloride. Reflux the mixture gently upon a water bath until all the acid dissolves (1-2 hours). Allow the solution to cool undisturbed and finally cool in ice. Collect the succinic anhydride, which separates in beautiful crystals, on a Buchner or sintered glass funnel, wash it with two 40 ml. portions of anhydrous ether, and dry in a vacuum desiccator. The yield of succinic anhydride, m.p. 118-119°, is 47 g. 

Method B. In a 500 ml. round-bottomed flask, provided with a reflux condenser protected by a cotton wool (or calcium chloride) drying tube, place 59 g. of succinic acid and 102 g. (94-5 ml.) of redistilled acetic anhydride. Reflux the mixture gently on a water bath with occasional shaking until a clear solution is obtamed ca. 1 hour), and then for a further hour to ensure the completeness of the reaction. Remove the complete assembly from the water bath, allow it to cool (observe the formation of crystals), and finally cool in ice. Collect the succinic anhydride as in Method A. The yield is 45 g., m.p. 119-120°. 

The appropriate succinic acid can be prepared by condensation of the iinsaturatod (yano ester with alcoholio potassium cyanide. 

The preparation of the cyclic ketone a-tetralone possesses a number of interesting features. Succinic anhydride is condensed with pure benzene in the presence of anhydrous aluminium chloride (slightly over two equivalents see 1 above) to yield (3-benzoylpropionlc acid ... 

The condensation of aldehydes and ketones with succinic esters in the presence of sodium ethoxide is known as the Stobbe condensation. The reaction with sodium ethoxide is comparatively slow and a httlo reduction of the ketonic compound to the carbinol usually occurs a shorter reaction time and a better yield is generally obtained with the more powerful condensing agent potassium ieri.-butoxide or with sodium hydride. Thus benzophenone condenses with diethyl succinate in the presence of potassium [Pg.919]

Anthracene and maleic anhydride. In a 50 ml. round-bottomed flask fitted with a reflux condenser, place 2 0 g. of pure anthracene, I 1 g. of maleic anhydride (Section 111,93) and 25 ml. of dry xylene. Boil the mixture under reflux for 20 minutes with frequent shaking during the first 10 minutes. Allow to cool somewhat, add 0 5 g. of decolourising carbon and boil for a further 5 minutes. Filter the hot solution through a small, preheated Buchner funnel. Collect the solid which separates upon coohng by suction filtration, and dry it in a vacuum desiccator containing paraffin wax shavings (to absorb traces of xylene). The yield of adduct (colourless crystals), m.p. 262-263° (decomp.), is 2-2 g. Place the product (9 10-dihydroanthracene-9 10-cndo-ap-succinic anhydride) in a weU-stoppered tube, since exposure to air tends to cause hydration of the anhydride portion of the molecule. 

A classical way to achieve regioselectivity in an (a -i- d -reaction is to start with a-carbanions of carboxylic acid derivatives and electrophilic ketones. Most successful are condensations with 1,3-dicarbonyl carbanions, e.g. with malonic acid derivatives, since they can be produced at low pH, where ketones do not enolize. Succinic acid derivatives can also be de-protonated and added to ketones (Stobbe condensation). In the first example given below a Dieckmann condensation on a nitrile follows a Stobbe condensation, and selectivity is dictated by the tricyclic educt neither the nitrile group nor the ketone is enolizable (W.S. Johnson, 1945, 1947). 

Cydopentane reagents used in synthesis are usually derived from cyclopentanone (R.A. Ellison, 1973). Classically they are made by base-catalyzed intramolecular aldol or ester condensations (see also p. 55). An important example is 2-methylcydopentane-l,3-dione. It is synthesized by intramolecular acylation of diethyl propionylsucdnate dianion followed by saponification and decarboxylation. This cyclization only worked with potassium t-butoxide in boiling xylene (R. Bucourt, 1965). Faster routes to this diketone start with succinic acid or its anhydride. A Friedel-Crafts acylation with 2-acetoxy-2-butene in nitrobenzene or with pro-pionyl chloride in nitromethane leads to acylated adducts, which are deacylated in aqueous acids (V.J. Grenda, 1967 L.E. Schick, 1969). A new promising route to substituted cyclopent-2-enones makes use of intermediate 5-nitro-l,3-diones (D. Seebach, 1977). 

Pyrrohdinone (2-pyrrohdone, butyrolactam or 2-Pyrol) (27) was first reported in 1889 as a product of the dehydration of 4-aminobutanoic acid (49). The synthesis used for commercial manufacture, ie, condensation of butyrolactone with ammonia at high temperatures, was first described in 1936 (50). Other synthetic routes include carbon monoxide insertion into allylamine (51,52), hydrolytic hydrogenation of succinonitnle (53,54), and hydrogenation of ammoniacal solutions of maleic or succinic acids (55—57). Properties of 2-pyrrohdinone are Hsted in Table 2. 2-Pyrrohdinone is completely miscible with water, lower alcohols, lower ketones, ether, ethyl acetate, chloroform, and benzene. It is soluble to ca 1 wt % in aUphatic hydrocarbons. 

Condensation with Aldehydes and Ketones. Succinic anhydride and succinic esters in the presence of different catalysts react in the gas phase with formaldehyde to give citraconic acid or anhydride and itaconic acid (94—96). Dialkyl acyl succinates are obtained by reaction of dialkyl succinates with C 4 aldehydes over peroxide catalysts (97). 

Succinic esters condense with aldehydes and ketones in the presence of bases, eg, sodium alkoxide or piperidine, to form monoesters of alkybdenesuccinic acids, eg, condensation of diethyl succinate with acetone yields ethyl 2-isopropyhdenesuccinate (eq. 3). This reaction, known as Stobbe condensation, is specific for succinic esters and substituted succinic esters (98,99). 

Friedel-Crafts Acylation. The Friedel-Crafts acylation procedure is the most important method for preparing aromatic ketones and thein derivatives. Acetyl chloride (acetic anhydride) reacts with benzene ia the presence of aluminum chloride or acid catalysts to produce acetophenone [98-86-2], CgHgO (1-phenylethanone). Benzene can also be condensed with dicarboxyHc acid anhydrides to yield benzoyl derivatives of carboxyHc acids. These benzoyl derivatives are often used for constmcting polycycHc molecules (Haworth reaction). For example, benzene reacts with succinic anhydride ia the presence of aluminum chloride to produce P-benzoylpropionic acid [2051-95-8] which is converted iato a-tetralone [529-34-0] (30). 

The diacids are characterized by two carboxyHc acid groups attached to a linear or branched hydrocarbon chain. AUphatic, linear dicarboxyhc acids of the general formula HOOC(CH2) COOH, and branched dicarboxyhc acids are the subject of this article. The more common aUphatic diacids (oxaUc, malonic, succinic, and adipic) as weU as the common unsaturated diacids (maleic acid, fumaric acid), the dimer acids (qv), and the aromatic diacids (phthaUc acids) are not discussed here (see Adipic acid Maleic anhydride, maleic acid, and fumaric acid Malonic acid and derivatives Oxalic acid Phthalic acid and OTHERBENZENE-POLYCARBOXYLIC ACIDS SucciNic ACID AND SUCCINIC ANHYDRIDE). The bihinctionahty of the diacids makes them versatile materials, ideally suited for a variety of condensation polymerization reactions. Several diacids are commercially important chemicals that are produced in multimillion kg quantities and find appHcation in a myriad of uses. 

FRANCHIMOND Cyano Succinic Acid Synthesis Condensation of a-haloesters to succinic acid derivalives in the presence of CN ... 

KNOEVENAGEL OOEBNER STOBBE Condensation Base catalyzed aldol condensation of aldehydes or ketones with an activated methylene group of a malonic ester (Knoevenagel Doebner) or a succinic ester (Stobbe)... 

In a 2-1. round-bottomed, 3-necked flask fitted with a stirrer and two large-bore condensers are placed 200 cc. of 50 per cent nitric acid and 0.25 g. of vanadium pentoxide. The flask is heated to 65-70° in a water bath (thermometer in water), and I cc. of cyclopentanone added. Oxidation is indicated by the production of brown fumes. The water bath is removed, and 42 g. (less the i cc.) of the cyclic ketone added from a dropping funnel through the condenser at the rate of a drop every three seconds. The heat of the reaction keeps the flask at about 70°. If the temperature drops, oxidation ceases until the ketone has accumulated, when it may proceed almost explosively. In such a case, or if the temperature is higher, much succinic acid is formed. After addition has been completed, the water bath... 

Ethyl oxalylsuccinate has been prepared by the condensation of ethyl oxalate with ethyl succinate in the presence of sodium ethoxide or of potassium ethoxide. The method described above is somewhat more convenient, and has given a higher yield of a better product, than one based upon sodium ethoxide, submitted by A. E. Martell and R. M. Herbst. 

Diethyl succinate was obtained by the submitters from Eastman Organic Chemicals and used without purification. The checkers obtained the ester from British Drug Houses, Ltd., and distilled it at 100° (11 mm.). In general, it is preferable to distill or crystallize and dry all esters before attempting acyloin condensations. 

Condensation of o-aminoacetophenone with maleic, succinic or phthalic anhydrides gave 117 whose bromination with CuBr2 gave the bromides 118. Column chromatographic separation of the respective maleimide derivative on silica gel gave the bromoquinoline 119 whereas the phthalimide derivative was obtained from 118 by cyclization with EtsN (93MI11). On the... 

Formal oxidation of pyrrolidine to the succinimide stage affords a series of compounds used as anticonvulsant agents for treatment of seizures in petit mal epilepsy. Knoevnagel condensation of benzaldehyde with ethyl cyanoacetate affords the unsaturated ester, 9. Conjugate addition of cyanide ion leads to the di-nitrile ester (10). Hydrolysis in mineral acid affords the succinic acid (11), presumably by decarboxylation of the intermediate tricarboxyllie acid. Lactamization with methylamine gives phensuximide (12). ... 

The utility of base catalyzed condensations of esters to give jS-ketoesters is well known. A straightforward example of this reaction is the intermolecular cyclization of diethyl succinate giving 2,5-dicarbethoxy-l,4-cyclohexanedione, which can in turn be easily decarboxylated to give 1,4-cyclohexanedione. 

I. 2,5-Dicarbethoxy-1,4-cyclohexanedione (7) A 500-ml, three-necked, round-bottom flask is fitted with a condenser (drying tube) and arranged for magnetic stirring. A solution of sodium ethoxide is prepared in the flask by the addition of sodium (9.2 g, 0.4 g-atom) in small pieces to 90 ml of absolute ethanol. The mixture is heated at reflux for 3 hours (oil bath) to complete the reaction. Diethyl succinate (34.8 g, 0.2 mole) is added to the hot solution in one portion exothermic ) and the mixture is refluxed for 24 hours. (A pink precipitate forms and persists during the reflux.)... 

The synthesis of porphyrins from dipyrrylmethenes was first developed by Fischer42 and his collaborators. Different variants of this method are available. For the preparation of centrosym-metric porphyrins 7, the self-condensation of 5-bromo-5 -methyldipyrrylmethene hydrobromides or perbromides 6 in organic acid melts like succinic acid, tartaric acid or formic acid at temperatures up to 200 °C can be used. 

Two hundred and seventy-six grams (94.3 cc., 1.72 moles) of bromine (Note 7) is now added as rapidly as possible through the dropping funnel, the rate of addition being so controlled that the Friedrichs condenser is continuously about half full of the refluxing liquid (Note 8). This operation takes about one hour (Note 9). After about 100 g. of bromine has been added, the dibromo-succinic acid forms rapidly and separates in tiny white needles. At the completion of the reaction there should be a slight excess of bromine, as indicated by the red color of the solution. Occasionally 5-10 g. of bromine has to be added at this point to insure an excess. 

Preparation of l,2-bis(trimcthylsilyloxy)cyclobutene from diethyl succinate (Riihlmann condensation using Na and TMSC1), and of 2-hydroxycyclo-Ibutanone. 

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