Ethyl Chloride
Formula: C2H5Cl
Preparation
Ethyl chloride is prepared by a nucleophilic substitution reaction. Ethanol is boiled with hydrochloric acid to form ethyl chloride, which is then distilled.
Reaction:
C2H5OH + HCl → C2H5Cl + H2O
Tests for Purity
- Acidity / Alkalinity: Since ethyl chloride is hydrophobic, it is fractionated with water to check acidity or alkalinity.
- Insoluble Chlorides: No turbidity should occur when tested with silver nitrate.
- Distillation Range: 12–12.5°C.
- Other Organic Compounds: After heating the sample in a crucible, no foreign organic impurities should remain.
- Non-volatile Material: Should be less than 0.01% w/w.
Assay
About 1.5 mL of cold ethyl chloride is placed into a tared pressure bottle containing 25 mL of 1N alcoholic potassium hydroxide. After sealing, heating, cooling, and adding phenolphthalein, the excess alkali is titrated with 1N HCl. A blank determination is also performed.
Note: Each mL of 1N alcoholic KOH is equivalent to 64.51 mg of C2H5Cl.
Uses
- Used as a local anaesthetic (cooling spray).
- Also used as an industrial and laboratory solvent.
Note: Information adapted from Indian Pharmacopoeia 2018. Students are advised to consult additional sources due to limited details in IP.
Detailed Notes:
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PATH: PHARMD/PHARMD NOTES/ PHARMD FIRST YEAR NOTES/ ORGANIC CHEMISTRY/ PHARMACEUTICAL ORGANIC CHEMISTRY/ ETHYL CHLORIDE (OR) ETHYLENE CHLORIDE.