Question

6-9

2 6. Which one of the following is the intermediate in the bromination of tolume (1)! (0) (0) (d) ch 대 75.1 LH Br Вт # Bm 7. Which is the correct order of reactivity of the following three compounds in brominaion reactions? Most reactive first, least reactive last. c . a-HH3 (a) 3>>>1 (b) 1>3>2 (e) >1>3 (d) 3>1>2 8. In the nitration of the following compound the bromine will add on which carbon? (a) 1 (b) 2 (e) 3 (d) 1 and 2 CHE - CH3 9. Provide the major product that results when benzene is treated with the following sequence of reagents: 1. Brz+ FeBr followed by 2. HNO3 + H2SO. (a) (b) 2 (c)3 (d) both 1 and 3 Ar ktor Elmo la & both a and a morte NO

Answer 1

6) During bromination of toulene there possibilities of two intermediates first if the electrophile attack at ortho position and other is at para position.So by looking the options we come across only II option is correct.

7)Since the order of reactivity depends on the mesomeric effect of the functional group so we have shown the order of mesomeric effect and come across d is correct.

8) Since methyl group is ortho- para directing but the para is block due to ketone functional group means ortho one be the position to attack similarly nitro group is meta directing group we can say that meta position of nitro is block by ketone and other side is ortho to methyl group.Again the ketone group is meta directing group so meta to ketone is ortho to methyl group but one meta is block by nitro. So all favourable combinations leads to ortho position attack.i.e

a)1 position to correct  

9) The first is the bromination of benzene to form bromobenzene and next step is the nitration of bromobenzene which results in ortho and para substitued nitro derivative product.But the major product will be the para nitro bromobenzene.

Correct option will be a.

Answed. Bromination of toulene have following intermediatert CH3 + Br" en CH3 13 (when ortho attack of electrophile) (when para attack of electoophile). Вт" 8Y I option is correct. Ans-7. Order of reactivity depends on the electron releasing tendency of group , so the order of electron releasing tendency cle tM tendency) :- to-ch) > to-c-cg) > terg) d) 37132 is correct. Ansam 8. CH₂ Bromination ONT z oferenz . So a I is the correct. I Ansa FeBrg Í + Bry – H₂SO4 ortho (Miner ( Minor Na para 7 Μαίου product product So a) is the correct. Scanned with CamScanner