Chemistry · Ch 14 — Haloalkanes and Haloarenes
Nomenclature
Nomenclature
Haloalkanes can be named by the common system -- naming the alkyl group followed by 'halide' (e.g. methyl iodide, ethyl bromide, tert-butyl chloride) -- or by the IUPAC system, applying the general nomenclature rules (Unit 11) with the halogen cited as a 'halo' prefix and the lowest locants given to the substituents. Vinylic and allylic examples follow the same rule set once the parent alkene chain is n …
| S.No | Structural formula | Common name | IUPAC name |
|---|---|---|---|
| 1 | CH3I | methyl iodide | Iodomethane |
| 2 | CH3CH2Br | ethyl bromide | Bromoethane |
| 3 | CH3CH2CH2F | n-propyl fluoride | 1-Fluoropropane |
| 4 | CH3-CHF-CH3 | iso-propyl fluoride | 2-Fluoropropane |
| 5 | CH3-CH2-CH2-CH2-Cl | n-butyl chloride | 1-Chlorobutane |
| 6 | CH3-CH(CH3)-CH2-Cl | iso-butyl chloride | 1-Chloro-2-methylpropane |
| 7 | CH3-CH(Cl)-CH2-CH3 | sec-butyl chloride | 2-Chlorobutane |
| 8 | CH3-C(Cl)(CH3)-CH3 | tert-butyl chloride | 2-Chloro-2-methylpropane |
| 9 | (CH3)3C-CH2-Br | neo-pentyl bromide | 1-Bromo-2,2-dimethylpropane |
| 10 | CH2=CH-Cl | vinyl chloride | Chloroethene |
| 11 | CH2=CH-CH2-Br | allyl bromide | 3-Bromopropene |
| 12 | ClCH2-CH2Cl | Ethylene chloride (ethylene dichloride) | 1,2-Dichloroethane |
Worked out. Book's practice box (no printed solution). i) CH2=C(CH3)-CH2-Cl; ii) the trisubstituted alkene CH3-CH=C(CH3)-CH(I)-CH3 drawn with the C1-methyl and the C4 iodo-chain on opposite sides of the double bond; iii) CH3-CH=CH-CH(F)-CH3 drawn trans (the C1-methyl and the C4 fluoro-chain on opposite sides). Working through them: (i) numbering from the =CH2 end gives the double bond the lower locant 1, so the name is 3-chloro-2-methylprop-1-ene; (ii) the higher-priority groups (C1-methyl on C2; the iodo-bearing C4 chain on C3) sit on opposite sides, so it is (E)-4-iodo-3-methylpent-2-ene; (iii) by the same CIP logic it is (E)-4-fluoropent-2-ene (own solutio …
Worked out. Book's practice box (no printed solution): draw i) 1-bromo-4-ethylcyclohexane (a cyclohexane ring with Br on C1 and an ethyl group on C4, a 1,4/para relationship around the ring); ii) 1,4-dichlorobut-2-ene (ClCH2-CH=CH-CH2Cl, a symmetric four-carbon chain with the double bond in the middle and Cl on both end carbons); iii) 2-chloro-3-methylpentane (CH3-CHCl-CH(CH3)-CH2-CH3) (own solutions, not printed in the textbook …