2.2- Dinaphthyl

Anth nthrones. Halogenated derivatives have been developed to improve the dyeing properties of anthanthrones, which have low tinctorial strength and poor affinity to cellulose fibers. The only example of commercial significance is Cl Vat Orange 3 [4378-614] (4) Cl 59300). This compound is prepared from l,l -dinaphthyl-8,8 -dicarboxyhc acid (173) with oleum and bromine as follows ... 

Cyclohexyl-[2- (bzw. 4)-methoxy-phenyl]- 410 Diaryl- 541 Dicyclohexyl- 274 Dinaphthyl-(l)- 411... 

Although diphenyl ether and dibenzofuran were very stable at 450°C, 2,2 -dinaphthyl ether was decomposed slowly and benzyl ethers completely. 

Although diphenyl ether and dibenzofuran were very stable for thermolysis at 450°C for 120 min, the rate of decomposition increased with increasing the number of benzene nucleus, that is, 2,2 -dinaphthyl ether was converted to the value of 23.3% and phenyl phenanthryl ether 64.8% at the same reaction conditions. 

The thermal decomposition of dibenzyl was not affected by the addition of phenol or p-cresol. In contrast, the decomposition of 2,2 -dinaphthyl ether increases remarkably in the presence of phenolic compounds as shown in Table III, and the effect seems to increase with increasing the electron donating property of substituent on the benzene nucleus. 

TABLE III EFFECT OF PHENOLS ON THE THERMAL DECOMPOSITION OF 2,2 -DINAPHTHYL ETHER AT 450°C FOR 60 MIN (2,2 -Dinaphthyl ether 11 mmole, Tetralin 225 mmole, Additive 150 mmole)... 

Diazotizing 106 and boiling the solution in the presence of copper powder affords 1,1 -dinaphthyl-8,8 -dicarboxylic acid (107), which is cyclized with aluminum chloride, but preferably with concentrated sulfuric acid at 30 to 40°C to produce anthanthrone. 

Chiral recognition experiments with dinaphthyl-crown ethers have been carried out in two different ways (Helgeson et al., 1973b Timko et al., 1978) ... 

The maximum observed free energy difference between two enantiomeric host-guest complexes in which one 1,1 -dinaphthyl element is the only source of chirality in the crown ether is about 0.3 kcal mol-1. Improvement of the free energy difference can be achieved by introduction of two such elements. Unfortunately crown ethers with three 1,1 -dinaphthyl groups did not form complexes with primary ammonium salts (de Jong et al., 1975). The dilocular chiral crown ether [294] forms complexes of different stability with R- and 5-cr-phenylethylammonium hexafluorophosphate. The (J )-J J -[284] complex was the more stable by 0.3 kcal mol-1 at 0°C (EDC value 1.77) (Kyba et al., 1973b). Crown ether [284] also discriminates between the two enantiomers of phenylglycine methyl ester hexafluorophosphate and valine methyl ester... 

A substantial increase in the enantiomeric differentiation is observed when the 3- and 3 -positions of the 1,1 -dinaphthyl or 1,1 -ditetralyl groups are substituted (Helgeson et al., 1974 Peacock and Cram, 1976 Peacock et al.,... 

Effect of substituents in Ws(dinaphthyl)-22-crown-6 at the 3,3 -positions on chiral recognition of RCH(COOCH3)NH3Xa... 

Extractions of aqueous solutions of racemic amino-acid ester salts with solutions of / -6/s(dinaphthyl)-22-crown-6 [284] in chloroform revealed the dependence of the enantiomeric distribution constant on the structure of the amino acid ester (Table 64). In order to limit the concentrations of complex in the aqueous phase, inorganic salts were added. In the case of tyrosine, serine and alanine no extraction of salt was observed obviously these salts form very hydrophilic complexes. The highest degree of chiral recognition was found with [284] and p-hydroxyphenylglycine methyl ester hexafluorophosphate [A(AG°)... 

The influence of the counterion on the stability of crown-ether complexes in general was reviewed in detail in one of the preceding sections. There it was shown to be an important parameter. The nature of the counterion in diastereomeric complexes of chiral crown ethers with primary ammonium salts also influences the chiral recognition. First of all it greatly determines whether salt can be extracted into the organic phase where the chiral discrimination takes place. In a series of experiments (Kyba et al., 1978) it was shown that when S,S -6zs(dinaphthyl)-22-crown-6 [284] in chloroform was equilibrated with racemic er-phenylethylammonium salts the type of anion also influences the degree of enantiomeric differentiation (Table 70). The highest... 

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