Question

Study Pr 3 Predict the major products of the following reactions. (a) 2,4-dinitrochlorobenzene + NaOCH3 (c) nitrobenzene + fuming sulfuric acid (e) p-methylanisole + acetyl chloride AICI, (g) 1,2-dichloro-4-nitrobenzene NaNH2 (i) p-ethyibenzenesulfonic acid +steam/H (b) phenol + tert-butyl chloride + AICl, (d) nitrobenzene + acetyl chloride +AlC1 (f) p-methylanisole + Br2, light (h) p-nitrotoluene + Zn + dilute HCl j) p-ethylbenzenesulfonic acid + HNO3, H2S + hot, concd. KMnO Ph-C-NHPh + CH,CH,-C-CI, AICI3 indane

Answer 1

CI OCH2 NO 2 NaOCH3 NO2 NO2 NO. 1-chloro-2,4-dinitrobenzene 1-methoxy-2,4-dinitrobenzene a) dinitro groups make benzene ring more electron deficient and hence Methoxy anion act as a nucleophile to give nucleophilic aromatic substitution product b) OH он tert. BuCI AICI3 CH3 phenol H3CCH3 4-tert-butylphenol

c) Nitrogorup is meta directing for electrophilic aromatic substitution NO NO Fuming -nitrobenzene-1-sulfonic acid H2SO4 SO3H nitrobenzene d) Nitrogorup is meta directing for electrophilic aromatic substitutioin NO NO H2C CI AICI3 nitrobenzene 1-(3-nitrophenyl)ethan-1-one e) resonance effect of OCH3 group is more stronger and hence major product is ortho substitution. Para position is blocked O H2C O 1-(2-methoxy-5-methylph enyl)ethan-1-one H2C CI CH AlCI3 p-methyl anisole CH CH

f) p-methylanisole contains methyl group attached to aromatic ring and hence in presence of light and bromine, the bromination occurs at benzylic position insted of on aromatic ring. This is because reaction follows via radical mechanism and benzyl radical is more stable Br2 1-(bromomethl)-4-methoxy benzene light p-methyl anisole CH Br g) This is a aromatic nucleophilic substitution reaction. The nitrogroup stabilizes the intermediate when NH2 anion attacks at para chlorine and hence the product is formed as a major product CI NH Cl NaNH2 Cl NO2 1,2-dichloro-4-nitrobenzene 2-chloro-4-nitroaniline

h) Zn, dil. HCl produces insitu hydrogen and it reduces the nitrogroup to amino group CH CH Zn, dil. HC NH2 4-methylaniline NO2 1-methvl-4-nitrobenzene i) This is a desulfonation reaction CH CH Steam/H-+ ethylbenzene 4-ethylbenzene-1-sulfonic acid SO2H j) Sulfonyl group is meta directing and ethyl is ortho directing CHa На No2 4-ethyl-3-nitrobenzene-1-su HNO3 H2SO4 fonic acid S0aH S03H

k) acylation will occuure at the phenyl ring attached to nitrogen. ње Cl NH NH AICI3 N-phenylbenzamide Нас H3C oxidation at benzylic position. hot, conc. OH KMnO4 он он