Dicarboxylic acid dichlorides

Dicarboxylic acid dichlorides with less than seven carbon atoms do not react to give tetraketones similar to 117, but instead undergo an intramolecular acylation (72) to give on hydrolysis the vinylogous acid anhydride (118), e.g., from succinyl chloride and the enamine (113). 

However, dicarboxylic acid dichlorides treated with iminophosphoranes (Scheme 116) show a substrate-dependent reaction. Thus, o-benzodiacetyl dichlorides (321) form chloroazepinones (322) only with A -arylimino-phosphoranes. N-Alkyliminophosphoranes, upon elimination of dichloro-triphenylphosphorane and subsequent Mumm rearrangement (71M168), give the cyclic imide (323) (90S149 91T53). 

Heterocyclic secondary enamines and dicarboxylic acid dichlorides undergo complex, ring-size-dependent annulation reactions that, in the case of ester 238 and phthaloyl chloride (Scheme 57), lead to lactone-containing derivative 239 (02T2821). 

The Schotten-Baumann reaction between dicarboxylic acid dichlorides and diamines can be performed not only in organic solvents, but also, by means of a special experimental technique known as interfacial polycondensation (see Examples 4-5 and 4-11). Both variants have the advantage of short reaction times at low temperature with simple equipment. 

Fully aromatic polyamides are synthesized by interfacial polycondensation of diamines and dicarboxylic acid dichlorides or by solution condensation at low temperature. For the synthesis of poly(p-benzamide)s the low-temperature polycondensation of 4-aminobenzoyl chloride hydrochloride is applicable in a mixture of N-methylpyrrolidone and calcium chloride as solvent. The rate of the reaction and molecular weight are influenced by many factors, like the purity of monomers and solvents, the mode of monomer addition, temperature, stirring velocity, and chain terminators. Also, the type and amount of the neutralization agents which react with the hydrochloric acid from the condensation reaction, play an important role. Suitable are, e.g., calcium hydroxide or calcium oxide. 

Partial aliphatic catenanes reported by Leigh et al. in 1996 exhibit an interesting solvent-dependent translational isomerism [29]. Stannylation of 43 converts the diol into 44, which is readily soluble in nonpolar solvents (Figure 17). Subsequent treatment with various aliphatic l,co-dicarboxylic acid dichlorides led to catenanes 45 and macrocycles bearing lipophilic chains. 

SCHEME 8 A STEPWISE ROUTE TO UNSYMMETRICAL MACROCYCLES. WITH 2,6-PYRIDINE DICARBOXYLIC ACID DICHLORIDE BUILDING BLOCK 17 IS FORMED WHICH IS PREORGANIZED FOR MACROCYCLIZATION AND THUS GIVES HIGHER YIELDS OF MACROCYCLE 18 AS COMPARED TO 13. THE INSET SHOWS THE HYDROGEN BONDING PATTERN IN THE PYRIDINE BUILDING BLOCKS AND THE EFFECTS IT HAS ON CONFORMATIONAL EQUILIBRIA AND... 

AND ITS LARGER OCTALACTAM ANALOGUE 26, WHEN THE REACTION SEQUENCE SHOWN IN SCHEME 8 IS REVERSED AND EXTENDED DIAMINE 25 IS REACTED WITH 2,6-PYRIDINE DICARBOXYLIC ACID DICHLORIDE. 

A molecule with an even more spectacular topology was obtained when extended diamine 13 was reacted with 2,6-pyridine dicarboxylic acid dichloride. This was just a reversal of the order of the reaction steps in Figure 3. As well as the expected tetralactam macrocycle, its larger analogue octalactam wheel and a knot were formed [15], It was very surprising that a knot which bears three crossing points in its molecular... 

Fig. 10 Dicarboxylic acid dichloride used by Voegtle in formulating chemical trefoil knot...

Dimethyl-l,3-dioxane-4,6-dione (Meldmm s acid) (O.lOmol) and pyridine (0.25 mol) were dissolved in 200 ml CH2CI2 and the mixture cooled with ice. Octadecyl-1,18-dicarboxylic acid dichloride (0.05 mol) dissolved in 50 ml CH2CI2 added over 15 minutes, and the reaction mixture stirred 30 minutes while being kept cool with ice. The mixture was then treated with 100 ml apiece 10% HCl and CH2CI2 and solvent removed under reduced pressure at ambient temperature. Thereafter, precipitated crystals were isolated by filtration, re-crystallized using CH2Cl2/diethyl ether, 1 5, and the product isolated, MP = 96-98 °C. H- and i C-NMR data supplied. 

In the furoquinone series, a new compound, isotanshinone, was isolated. The compound has a benzo analog skeleton of 84 (87MI7). The preparation of 3-methylbenzofuran-4,5-dione is described and its dienophilicity was studied (87TL3427). A direct synthesis of some heterocyclic quinones is reported. The method is a direct one-step ortho-bisacylation of hydroquinones under very mild conditions and in the presence of AICI3. Examples of acylation with furan-3,4- and pyridine-3,4-dicarboxylic acid dichlorides are described (87TL1533). 

The reaction of dicarboxylic acid dichlorides with aryl cyanides in the presence of antimony(V) chloride gives his(1,3,5-oxadiazinium) salts 9a-l whose colors range from yellow to brown.67 The stability of the salts increases with the distance of the heterocyclic rings from each other. 

A solution of SbCl5 (59.85 g, 200 mmol) in cci4 (100 mL) was added dropwise to a vigorously stirred solution of an aryl cyanide (400 mmol) in CCI4 (250 mL) at ca. 0 °C. A precipitate appeared, which dissolved on warming to 75 °C. A solution of dicarboxylic acid dichloride (100 mmol) in CC14 (200 mL) was added and the mixture was heated under reflux for 5 h. The precipitated product was filtered off and washed several times with hot CC14. 

Bisoxadiazinium salts 9m-r are prepared from dicarboxylic acid dichlorides and various aryl cyanides by a slightly different procedure.68... 

A solution of a dicarboxylic acid dichloride (5 mmol) in CH2C12 (10 mL) was cooled to — 40°C and treated with a solution of SbCls (3.0 g, 10 mmol) in CH2C12 (10 mL), followed by a solution of aryl cyanide (20 mmol) in CH2CI2 (10 mL). The mixture was allowed to warm to 20 °C and stirred for several hours until its IR spectrum no longer showed nitrile absorption at 2300-2200 cm. The precipitated product was filtered off and washed with EtOH (2 x 25 mL). 

Bis(oxadiazinium) salts 10 containing four dialkylamino substituents are readily obtained by the action of dicarboxylic acid dichlorides on dialkylcyanamides in the presence of Lewis acids.59... 

Bis(mcthylsulfanyloxadiazinium) salts 11 are also obtained from various dicarboxylic acid dichlorides and methyl thiocyanate.69... 

Dicarboxylic acid dichlorides can be obtained in very good yield from cyclic dicarboxylic thioanhydrides, which is useful when the latter are readily accessible. 

Another important group of bis(naphthalic anhydrides) - the so called bis(ketonaphthalic anhydrides) - was formed by the Fri lel-Crafts reaction between aromatic dicarboxylic acids dichlorides and two-fold molar amounts of acenaphthene and subsequent oxidation of tte obtained bis-acenaphthyls to bis(ketonaphthalic anhydrides) [111-115] according to heme 24. 

The interfacial polymerization of dithiols with dicarboxylic acid dichlorides gives polythioesters of high molecular weight [3b]. 

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