The invention discloses an efficient preparation method of
tetracaine, which comprises the following steps: 1, reacting
para aminobenzoic acid, 1-bromobutane and
triethylamine, concentrating under reduced pressure, adding an
organic solvent and water, performing hot extraction and liquid separation, cooling an organic phase to separate out a
solid, adding an acidic
aqueous solution, cooling to crystallize, filtering and
drying to obtain 4-butyl
aminobenzoic acid butyl ester; 2, 4-butylaminobenzoic acid butyl ester, water,
alcohol and
sodium hydroxide are subjected to a reaction; decompressing and concentrating to remove the
solvent, adding water for dissolving, acidifying with
hydrochloric acid to separate out a
solid, filtering and
drying to obtain 4-butylaminobenzoic acid; 3, 4-butylaminobenzoic acid, N, N-
dimethylethanolamine, a condensing agent or a hydroxyl activating agent and a reaction
organic solvent react; adding an alkaline
aqueous solution for washing and liquid separation, carrying out vacuum concentration on an organic phase, adding a refining
solvent into a concentrate, heating, adsorbing with
activated carbon, cooling for
crystallization, filtering and
drying to obtain a
tetracaine finished product; the
reaction temperature can be reduced, and the
energy consumption is low; and the obtained product has high purity and high yield.