InterviewSolution
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InterviewSolution
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What is the action of bromine in the presence of sodium hydroxide on primary, secondary and tertiary nitroalkanes ? |
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Answer» SOLUTION :(1) Primary nitroalkanes react with HALOGENS (Cl or Br) in the presence of alkali to give mono and di halonitroalkanes. `underset(1^(@)"nitroalkane")(2R-CH_(2)-NO_(2))+2Br_(2)+2NAOH underset(-H_(2)O)overset(-NaBr)toR-underset(Br)underset(|)CH-NO_(2) underset("1,1-dibromonitroalkane")(underset({:(-NaBr),(-H_(2)O):})overset(Br_(2)//NaOH)to R-underset(Br)underset(|)overset(Br)overset(|)C-NO_(2))` `underset("nitroethane")(2R-CH_(2))-NO_(2) underset({:(-NaBr),(-H_(2)O):})overset(Br_(2)//NaOH)to underset("bromonitroethane")(CH_(3)-underset(Br)underset(|)CH-NO_(2)) underset("1,1-dibromonitroethane")(underset({:(-NaBr),(-H_(2)O):})overset(Br_(2)//NaOH)to CH_(3)-underset(Br)underset(|)overset(Br)overset(|)C-NO_(2))` Nitromethane gives a trihalogen derivative called chloropicrin.Chloropicrinis an IMPORTANT insecticide. `underset("nitromethane")(CH_(3)NO_(2)+)3Cl_(2)+3NaOH to underset("chloropicrin")(C Cl_(3)NO_(2)+)3NaCl+3H_(2)O` (2)Secondary nitroalkanes react with halogens (Cl or Br)in the presence of alkali to give monohalonitroalkanes. `underset(2^(@)"Nitroalkane")(R_(2)CHNO_(2)) overset(Br//NaOH)to underset("monobromo derivative")(R-underset(R)underset(|)overset(Br)overset(|)C-NO_(2)+NaBr)+2H_(2)O` `CH_(3)-underset(H)underset(|)overset(CH_(3))overset(|)C-NO_(2)overset(Br_(2)//NaOH)toCH_(3)-underset(Br)underset(|)overset(CH_(3))overset(|)C-NO_(2)+NaBr+2H_(2)O` (3) Tertiary nitroalkanes do not react with bromine. |
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