Question

Chapter 4 4.21 Name the following compounds Chapter CH CHO para clara tolnene 4.22 Give the structures and names for all possible a trimethylbenzenes 42,4-trimethyl. 7. CH3 CH3 ct? ( 6 1,3,5 CH3 YCH3 CH3 4.26 The structure of the nitro group (-NO2) is usually shown as . yet experiments show that the two nitrogen-oxygen bonds have the same length of 1.21 A. This length is intermediate between 1.36 A for the N-O single bond and 1.18 A for the N=O double bond. Draw structural formulas that explain this observation. 7 4.30 Write out all steps in the mechanism for the reaction of a) H2C --CH3 + HNO3 (H2SO, catalyst) -CH3 + t'butylchloride + AlCl3

Answer 1

4.21) Name of the compounds:

B)

CHO Br1 3-bromobenzaldehyde

D)

CH3 1,4-dichloro-2-methylbenzene

F)

CH3 NO2 1-methyl-2-nitrobenzene

4.22) a. All possible structures and names of trimethylbenzene

CH3 CH3 CH3 H2C CH3 2 CH3 1,2,3-trimethylbenzene mesitylene CH3 1,2,4-trimethylbenzene

4.26) A bond between two Nitrogen-Oxygen bonds are same due to conjugation.

Or Resonance Structure

4.30) a) Step 1: Formation of Nitronium ion

NO2 HNO3 + H2SO4 | + HSO, NO,+

Step2: Attack of Nitronium ion

CH3 __NO₂ + NO + = CH3 CH3

Step 3:

CH3 CH3 NOZ HO CH3 1,4-dimethyl-2-nitrobenzene CH

b) Step 1: Formation of Carbocation (tert-butyl carbocation)

t-Buci + AlCl3 = t-Bu-C1-AlCl3 = t-But + AICI

Step 2: Formation of σ-complex

CH3 CH3 ♡ A1C14 + t-Bu = methylbenzene

Step 3:

CH3 CH3 AICI, + AlCl + HC H. t-Bu 1-(tert-butyl)-4-methylbenzene o-complex