Chloro group, directing effect

Chirality center, 292 detection of, 292-293 Eischer projections and, 975-978 R,S configuration of, 297-300 Chitin, structure of, 1002 Chloral hydrate, structure of, 707 Chloramphenicol, structure of, 304 Chlorine, reaction with alkanes, 91-92,335-338 reaction with alkenes, 215-218 reaction with alkynes, 262-263 reaction with aromatic compounds, 550 Chloro group, directing effect of, 567-568... 

Answer Methyl group is weakly activating, and chloro is weakly deactivating. Thus, the two groups have only small effects on the rate of reaction. The methyl group directs the electrophile to two possible positions ortho and para to it. The chloro group directs the electrophile... 

Whereas in benzene chemistry halogen substituents are ortho-para directing because of their weak donor effects, in thiophene the +M effect is strongest across the 2,3-bond. This means that a 2-chloro group gives... 

The heterocycle formed in the cyclocondensation reactions of 2-acetylenyl-l-chloro-9,10-anthraquinones or 5-acet-yleneyl-3-(diethylamino)-l,4-naphthaquinones with hydrazine is influenced by the presence of a heterofunctional OH group in the acetylenic substituent. This directive effect was used in the synthesis of naphtha [2,3- ]cin noline-4,7,12-triones and 4//-naphtho[ 1,8-z/7]-l, 2-dia/cpin-8-oncs <2000MC188>. 

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