Lidocaine

 

Lidocaine
aka Xylocaine

Chemical formula	C14H22N2O
OTP appearance	white solid
Molar Mass(g/mol)	234.34
Melting Point(°C)	68.5
Solubility in water(g/L)	0.41
Solubility in ethanol(g/L)	misc
NFPA 704	0 0 0

Uses

Primary

• Pharm: WHO LEM, local anesthetic lidocaine

Natural occurrence

• Does not occur naturally.

Hazards

• systemic (non-local) exposure include CNS depression and pardoxical excitation - e.g. bronchospasm and dyspnea, anxiety and depression

Production

Synthesis

1. Dissolve 2,6-Xylidine in glacial acetic acid
2. Add chloracetyl chloride

   C₆H₃(CH₃)₂NH₂ + ClCH₂COCl

   {CH₃COOH

   →

   }

   C₆H₄(CH₃)₂N(H)C(O)CH₂Cl

3. precipitate with sodium acetate, wash with cold water
4. filter
5. discard filtrate
6. reflux residue with diethylamine in toluene at 140°C for an hour

   C₆H₄(CH₃)₂N(H)C(O)CH₂Cl + NH(Et)₂

   {toluene

   →

   140°C, 1h}

   C₆H₄(CH₃)₂N(H)C(O)CH₂N(Et)₂ + HCl

7. Cool to room temperature
8. wash product with water several times
9. separate and discard aqueous layer
10. Add dilute hydrochloric acid
11. separate organic layer and discard
12. Neutralize with sodium hydroxide, keeping temperature between 10-20°C
13. filter
14. discard filtrate
15. recrystallize from warm/iced hexane