2.3.4.5- Tetrachlorobenzoic acid

Primary starting materials for this condensation reaction are 3,3,4,5,6,7-hexa-chloroisoindoline-l-one (40) and 2-cyano-3,4,5,6-tetrachlorobenzoic acid methyl ester (41) ... 

Fenacf 2.3.6- TBAf 2.3.5.6- TBA Amibenf 2.3.6- trichlorophenylacetic acid 2.3.6- trichlorobenzoic acid 2.3.6.6- tetrachlorobenzoic acid 3,amino-2,6-dichlorobenzoic acid... 

While 2/f-heptachlorotoluene hydrolyses (to 1,2,3,4-tetrachlorobenzoic acid), 2//,2 //-dodecachlorobibenzyl, under the same conditions, does not (Ballester et al., 1959b). This result can be accounted for as in (21a). The adverse electronic effect of the trichloromethyl group on the stability of the carbenium-ion intermediate in the hydrolysis of perchloro-p-xylene to tetrachloroterephthalic acid in concentrated H2SO4 becomes insignificant compared with the steric assistance (Ballester et al., 1959b). 

Peracetic acid oxidation of benzo[g]quinoxaline does not give an N-oxide/ and oxidation of the 5,10-dione with chromium trioxide in glacial acetic acid, or 40% sulfuric acid, yields the 2,3-dioxo derivative 15. The latter compound gives 2,3,5,10-tetrachlorobenzo[g]quinoxaline (16) on treatment with phosphorus pentachloride. ... 

PHYSICAL PROPERTIES colorless to light-tan crystalline solid odorless usually has 2,3,7,8-tetrachlorobenzo-p-dioxin (TCDD) as a minor component soluble in alcohol insoluble in water very slightly soluble in petroleum ether forms water-soluble sodium and atkanolamine salts commercial products are usually in the form of esters or amines, often in mixture with 2,4-dichlorophenoxyacetic acid (2,4-D) MP (151-153°C, 304-307°F) BP (decomposes above melting point at 760 mmHg) DN (1.80 g/cm at 20°C) SG (1.80) VD (NA) VP (< 1 x 10 mmHg at 20°C). 

For electrophilic substitution reactions, only the benzene ring carbon atoms are available. Thus chlorination with a mixture of concentrated hydrochloric and nitric acid yields 4,5,6,7-tetrachlorobenzo-triazole, whereas nitration gives mainly 4-nitrobenzotriazole. Action of KMn04 oxidatively opens the benzene ring and produces l,2,3-triazole-4,5-dicarboxylic acid. 

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