Classification and Nomenclature of Organic Halides

1. ORGANIC HALIDES CHAPTER 6 Presented By: Cyra Mae R. Soreda

2. CLASSIFICATION AND NOMENCLATURE OF ALKYL HALIDES COMMERCIALLY AND INDUSTRIALLY IMPORTANCE OF HALIDES

3. What Is an Alkyl Halide An organic compound containing at least one carbon-halogen bond (C-X) X (F, Cl , Br, I) replaces H Can contain many C-X bonds 3

4. Hydrocarbons can also contain other atoms, such as halogens ( F, Cl , Br, I ). Halogen atoms are treated like branching alkyl groups. Halogen Group Name F fluoro C chloro Br bromo I iodo

5. CLASSIFICATION OF ALKYL HALIDES An alkyl halide is classified according to the kind of carbon that bears the halogen. Alkyl halides are classified into three classes: Primary Alkyl Halide (Iº RX) Secondary Alkyl Halide (2º RX) Tertiary Alkyl Halide (3º RX)

6. PRIMARY ALKYL HALIDE     When one hydrogen atom of methyl group is replaced by an alkyl group, then the carbon of the substituted methyl is called Primary carbon atom. CH 3 -CH 2 -I (Ethyl iodide)  For example:

7. SECONDARY ALKYL HALIDE When two hydrogen atoms of methyl group are replace by any alkyl group, then the carbon atom of substituted methyl is called secondary carbon atom. . For example:

8. TERTIARY ALKYL HALIDE   When three hydrogen atoms of methyl groups are replaced by any alkyl group, then the carbon atom of the substituted methyl is called Tertiary carbon atom. For example:

9. Classify These :

10. Classify These:

11. NOMENCLATURE OF ALKYL HALIDES The two that are most widely used are: SYSTEMATIC NAME (IUPAC name) ALTERNATIVE NAME (common names) Both types can be applied to alcohols and alkyl halides.

12. Naming Alkyl Halides Find and name the parent chain. As naming alkanes, select the longest chain as the parent chain. Number the parent chain. Always number the chain beginning at the end nearer the first substituent, regardless of whether t is alkyl or halo. 12

13. If more than one of the same kind of halogen is present, number each and use of the prefixes di -, tri-, tetra-, and so on. For example, 1,3-dichloro-3-methylbutane

14. If different halogens are present, number each according to its position. List all substituents in alphabetical order .

15. Naming if Two Halides or Alkyl Are Equally Distant from Ends of Chain Begin at the end nearer the substituent whose name comes first in the alphabet 15

16. Learning Check: Give names for the following: 16

17. Solution: Give names for the following: 17 Iodobutane 1-chloro-3-methylbutane 1,5-dibromo-2,2-dimethylpentane 1,3-dichloro-3-methylbutane 1-chloro-3-ethyl-4-iodopentane 2-bromo-5-chlorohexane

18. ALTERNATIVE NAMES or COMMON NAMES Treat halogen as parent with alkyl side group Name as alkyl halide. Useful only for small alkyl groups. 18

19. Prefixes – the Halides The family called alkyl halides does not have a suffix. Halides are always named as prefixes. Fluorine is called “ fluoro ” Chlorine is called “ chloro ” Bromine is called “ bromo ” Iodine is called “ iodo ”

20. COMMON Nomenclature of Alkyl Halides Name the alkyl group and the halogen as separate words ( alkyl + halide ) CH 3 F CH 3 CH 2 CH 2 CH 2 CH 2 Cl CH 3 CH 2 CHCH 2 CH 2 CH 3 Br H I

21. Learning Check: Give names for the following: 21 butyl iodide) ( isopentyl chloride)

22. “Trivial” Names CH 2 X 2 called methylene halide. CHX 3 is a haloform. CX 4 is carbon tetrahalide. Examples: CH 2 Cl 2 is methylene chloride CHCl 3 is chloroform CCl 4 is carbon tetrachloride. => Chapter 6 22

23. Dihalides Geminal dihalide : two halogen atoms are bonded to the same carbon Vicinal dihalide : two halogen atoms are bonded to adjacent carbons.

24. Uses of Alkyl Halides Solvents - degreasers and dry cleaning fluid Reagents for synthesis of other compounds Anesthetic: Halothane is CF 3 CHClBr CHCl 3 used originally (toxic and carcinogenic) Freons , chlorofluorocarbons or CFC’s Freon 12, CF 2 Cl 2 , now replaced with Freon 22, CF 2 CHCl, not as harmful to ozone layer. Pesticides - DDT banned in U.S.

25. S ome uses: Fire-resistant solvents Refrigerants Pharmaceuticals and precursors

26. To God be the Glory! Thank you for listening!