Tetracaine hydrochloride is a white crystalline powder; odorless, slightly bitter in taste, with numbness to the tongue. The molecular formula is C15H15CIN2O2 Relative molecular mass: 300.8242.
Tetracaine hydrochloride is readily soluble in water and can also be dissolved in ethanol. Insoluble in ether and benzene, melting point is 147~150℃. In medicine, it is sometimes used as anesthesia for the removal of loose teeth, small mucosal masses, or small polyps. The amount used varies according to the type of use. Topical local anesthesia, 1% solution spray or smear: infiltration local anesthesia. 0.025%~0.03% solution; nerve conduction block. 0.1%~0.3% solution; epidural block 0.15%~0.3% solution, with lidoca hydrochloride The highest concentration is 0.3% when used in combination; for subarachnoid block, 10-15 mg is mixed with cerebrospinal fluid and injected. Extreme, infiltrating local anesthesia, nerve conduction block, 0.1g at a time.
Special reminder: Large doses can cause inhibition of the cardiac conduction system and central nervous system.
1. Intermediate 1: N, N-dimethylethanolamine hydrochloride
1) 300 g of dichloromethane and 95 g of thionyl chloride were added. Add it to the bottle, after the feeding is completed, cool down to about 0~5℃.
2) Start adding 68 g of N, N-dimethylethanolamine dropwise with a constant pressure dropping funnel. The dropwise temperature was controlled at 0~5°C.
3) After the dropwise addition is completed, stir for 1h, then heat up to about 40°C for reflux, and the reflux time is about 2h.
4) After refluxing, carry out normal pressure kohlrabi distillation, kohlrabi distillation to 55 ℃, and carry out vacuum distillation.
5) When the temperature does not exceed 55℃, distill until no liquid is produced, add 150g of ethanol.
6) Reflux, about half an hour later, to cool down.
7) Cooldown to 0~5℃ and stir for 2h. Then filter and dry. About 80 g of product are obtained.
8) The mother liquor is concentrated, 90 g of ethanol is distilled out for recovery, and then the product is frozen and separated. A total of 99g of dried products can be obtained from step 7. Appearance is white or white. The content is greater than 97%.
The above is the operation steps of intermediate 1 in the process. If you want to know the subsequent operation steps, please continue to pay attention to our industry knowledge, and we will continue to update the preparation method of tetracaine hydrochloride.