MCQ
Which among the following is the strongest $o, p-$directing group
- ✓$OH$
- B$Cl$
- C${C_6}{H_5}$
- D$Br$
✓
Answer
Correct option: A.
$OH$
a
Meta directing deactivators $\,<\,$ Ortho-Para directing deactivators (halogens) $\,<\,$ Ortho -Para directing Activators
Meta directing deactivators $\,<\,$ Ortho-Para directing deactivators (halogens) $\,<\,$ Ortho -Para directing Activators
Activator-An atom or molecule capable of increasing electron density on benzene ring either by hyper conjugation or by mesomeric effect $+R$.
Halogen are dectivator due $-I$ effect so their reactivity is less than of benzene but Ortho-Para directing due to $+R$ mesomeric effect.
Deactivates decreases electron density on benzene ring so electrophile can attack on meta position with difficulty.
Now the order
(Meta directing deactivators)
$- NO _2\,<\,- CN \,<\,- SO _3 H\, <\,- COCH_3\,<\,- COOH \,<\,- COOCH _3\,<\,- COH \,<\,$
( $OP$ deactivator)
$- I\, <\,- Br \,<\,- Cl\, <\,- F \,<\,$
($OP$ activators)
$- H \,<\,- ph \,<\,- CH _3\,<\,- COCH _3\,<\,- N \left( CH _3\right)_3\,<\,- OH \,<\,- NH _2$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
When $HgI_2$ is added to aqueous solution of $KI$, then the
→If the potential energy of the electron is $-10\,eV$ what is total energy? ................ $\mathrm{eV}$
→At $600\,K , 2\,mol$ of $NO$ are mixed with $1 mol$ of $O _{2}$.
→$2 NO _{( g )}+ O _{2}( g ) \rightleftarrows 2 NO _{2}( g )$
The reaction occurring as above comes to equilibrium under a total pressure of 1 atom. Analysis of the system shows that $0.6 mol$ of oxygen are present at equilibrium. The equilibrium constant for the reaction is $.........$(Nearest integer).
Total number of stereoisomers of the compound $1-$ bromo $-3-$ chloro cyclobutane
→The equivalent weight of $H_3PO_4$ in following reaction is
$H_3PO_4 + Ca(OH)_2 \to CaHPO_4 + 2H_2O$
→$H_3PO_4 + Ca(OH)_2 \to CaHPO_4 + 2H_2O$
The $IUPAC$ name of the compound $Br(Cl) CI\cdot CF_3$ is :
→Which one of the following complexes is an outer orbital complex
→Atomic no. : $Mn = 25,\,Fe = 26,\,Co = 27,\,Ni = 28$
A solution of sodium acetate in water will
The product of following reaction is
→$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3} - C - CH = C{H_2}\,\,\,\,\,} \\
{\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,\,\,C{H_{3\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}}}
\end{array}\xrightarrow[{(ii)\,NaB{H_4}}]{{(i)\,Hg{{(OAc)}_2};{H_2}O}}$
The electrophile involved in the below reaction is
