Benzocaine hydrochloride is the hydrochloride form of the local anesthetic benzocaine. Benzocaine hydrochloride Its pharmacological action is the same as that of benzocaine, but its anesthetic effect is weaker than that of procaine. Local absorption is slow and the effect is long-lasting. Because it is insoluble in water, Benzocaine hydrochloride it cannot be used as infiltration anesthesia, and it has analgesic and antipruritic effects. Benzocaine is also known as ethyl para-aminobenzoate, sinacecine. Those precipitated from water are colorless or white orthorhombic needle-like crystals or crystalline powders, and those precipitated from ether are square crystals. Odorless. Bitter taste. Relative Molecular Mass 165Chemicalbook.19. Melting point 92 ℃. The boiling point is 310°C, 183～184°C (1.87×103Pa). Insoluble in water, soluble in ethanol, ether and chloroform, also soluble in almond oil, olive oil and dilute acid. Stable in air. Using p-nitrotoluene as raw material, in sulfuric acid, it is oxidized with sodium dichromate to generate p-nitrobenzoic acid, which is esterified with ethanol. In , use iron powder to reduce at 85～95 ℃, can get benzocaine crude product. After separation, it was washed with water and purified by recrystallization from ethanol.