Benzoic acid, phenylesters

The l.-lc s deviate in their mesogenic groups (benzoic acid bi-phenylester and benzoic acid phenylester). 

The liquid crystalline side chain polymers investigated have either a polysiloxane (compounds SiCl and SIGN) or a polyacrylic (compound AcCN) polymer chain. These are coupled via flexible spacers with the mesogenic p-substituted benzoic acid phenylester groups. SiCl and SiCN are copolymers with p-methoxy components in excess. 

Guanidino and amidino phenylesters of substituted benzoic acids act as temporary inhibitors of serine proteases and may serve for the preparation of stable acyl enzymes acting as prodrugs [44]. The enzymes inactivated by active-site acylation regain their activity via deacylation in physiological environment. This opens up new pharmacological aspects to the acylated enzymes trypsin and related serine proteases and their action as proenzymes. 

Numerous individual substances were detected only in Ru04 extracts e.g. di- to pentachlorinated benzenes, 4-chlorobenzoic acid and 2,4-dichlorobenzoic acid 24, hexachlorocyclohexanes (a-,P-,y- and 5-HCH) 22, a technical mixture obtained during the synthesis of lindane, and the plasticizers alkylsulfonic acid phenylesters 23. These plasticizers were recently identified in riverine sediments (Franke et al. 1998). Furthermore, nitro-substituted benzoic acid and alkylated phenols 24 were observed. The occurrence of aromatic nitro compounds as a result of the oxidation of anilines can be excluded due to the contemporary appearance of amino compounds, e.g. 4-aminobenzoic acid or N-ethylaniline. However, the origin as well as the emission pathway of these compounds is still unknown. 

Homopolymers. Phenylesters of benzoic acid were chosen as mesogenic groups for the synthesis of suitable monomers. The acryloyl- and the methacryloyl moieties were used as polymerizable groups. The flexible spacer was an alkyl chain or an alkyloxy chain of varying length. Thus a homologous series of p-"(2-methylpropenoyloxyalkyoxy) benzoic acid -p substituted phenyl esters 1 was prepared. The monomers were synthesized by the standard methods as follows ... 

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