Bis-acid chlorides

It should be noted that the host structures were prepared from the simple monoazacrowns by acylating with a bis-acid chloride followed by hydride reduction. 

In an interesting variation on this theme, the bis acid chloride of diethylmalonate (138) is condensed with the 0-methyl ether of urea to afford the imino ether of the barbituric acid (139). Heating this ether at 200°C results in 0 to N migration of the methyl group and formation of metharbital (140). ... 

Cefpimizole (51) appears to be less active in vitro than cefotaxime and cefoperazone and to have a somewhat narrower activity spectrum although some strains of Pseudomonas are susceptible. It is not orally active, but its performance in vivo appears superior to what would be expected from its in vitro data. Its synthesis begins by acylation of cephaloglycin (48) with the bis acid chloride of imidazole-4,5-dicarboxylic acid (49) to give amide 50. The acetyl moiety at C-3 of this intermediate is displaced with 4-pyridineethanesulfonic acid and sodium iodide to give cef-pimazole (51) [16]. 

The template in this case not only acts as directing agent but also is a component of the final assembly. By reacting covalently with the bis(acid chloride), the... 

A similar approach was employed by Leigh [54] to prepare catenane 15 in one step by reacting bis(acid chloride) 11 with bis-amine 16 under high dilution conditions (see Scheme 10). 

Scheme 22 Cross-coupling reaction of Ar3Bi with bis-acid chlorides...

Examples where the phenolic hydroxy groups were utilized include the preparation of lignin epoxies by reaction with epichlorohydrin (2), esterifications with bis-acid chlorides (3) and cyanuric chloride (4), and polymerization with aziridines (5). 

By appending crown ether moieties to the amidopyrrole skeleton it had been shown that it is possible to both enhance the binding of anions to the cleft by the introduction of caesium cations but only with a limited degree of success (Figure 16).13 Compounds 16 and 17 were synthesized by reaction of the 4 -aminobenzo-15-crown-5 with the 2-methyl-5-mono-acid chloride-3,4-diphenylpyrrole and the analogous 2,5-bis-acid chloride in 28 and 33% respective yields. 

Diphenylphosphoryl azide (DPPA) 58 was first introduced as a reagent for peptide synthesis by Yamada in 197233 and has been widely used since it gives good yields and very little racemization. It may also be used to bring about a modified Curtius reaction in which a carboxylic acid, R CC H and an alcohol, R2OH, react in the presence of triethylamine to afford the carbamate R1 NHCO2R2.33 In Protocol 15, the use of DPPA to form a macrocyclic lactam 61 is illustrated. The 82% yield of the product using this method should be compared with the value of 24% for reaction of the bis(acid chloride) of 59 with the diamine 60. 

The secondary amino groups of low molecular hemiporjrfiyrazine [from 1,2-dicy-anobenzene and (104 a) react with bis-(acid chlorides) in dimethylacetaminde/triethyl-amine at low temperature to polyamidohexaazacyclanes (112). In (112) the center is blocked against metal introduction ... 

This system was prepared in 23% yield via the condensation reaction between the bis(acid chloride) form of sapphyrin 5.110 and bis(aminopropyl)diaza-18-crown-6 (5.128) (Scheme 5.6.5). It was hoped that this crown sapphyrin system might function as a ditopic ligand, capable of coordinating simultaneously both cationic and anionic substrates. To date, some preliminary evidence in favor of this proposal has been obtained. For instance, in work involving NH4F as the substrate, it was found that NH4" and F are simultaneously bound by the crown sapphyrin receptor. However, at present the structural nature of this proposed interaction remains indeterminate. 

Polycondensates 27 and 28 (Fig. 9-22), incorporating either the 1,3- or 1,1 -disubstituted ferrocene unit, were prepared by solution polymerisation. Polymers 27 [25] were obtained by reaction of the novel monomer 29 [25] (Fig. 9-23) with the desired bis(acid chloride) 31 (Fig. 9-23) in refluxing CH2CI2 in the presence of triethylamine. Polymers 28 [25] were prepared following the same procedure from bis-phenol 30 [16] (Fig. 9-23). 

Scheme 8.27 Soluble oligomeric bis acid chloride (OBAC).

The bis(acid chloride) of 2,2 -dithienylmethane-5,5 -dicarboxylic acid condenses with 5-substituted 2-alkylaminothiophenols to give cyanine dyes of general structure 85.112... 

The reaction between dibutyltin oxide and bis-thiols leads to cyclic products including the six-membered ring product 27 (Scheme 8) <2000PSA3656>. Reaction of 27 with bis-acid chlorides affords the polymers 28. 

Battersby et al. have prepared a series of strapped porphyrins bearing variously substituted pyridine ligands Reaction of the porphyrin bis-acid chloride 180 with the corresponding pyridine diol 207 gave the ester-linked pyridine straps 208 a-c in up to 38% yield (Scheme 62). The molecular structure of a crystalline side-product of these syntheses is shown in Fig. 11 . A cytochrome P450 model was prepared similarly (Scheme 63). A suitably functionalized diol 211 was reacted under high dilution with the bis-acid chloride of mesoporphyrin II (180) to give the strapped porphyrin 212 in 25%... 

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