Physical and chemical properties
Colorless crystal, melting point 128~129℃, boiling point 288℃. Soluble in water, alcohol and hot benzene, slightly soluble in ether.
Function and use
This product is used as a co-solvent in pharmaceuticals to increase the solubility of tetracycline hydrochloride and other drugs in water.
Benzamide is an important intermediate compound that is widely used in industries such as dyes, medicines and pesticides. It is extremely photostable and is extremely difficult to degrade once it enters the environment and is chronically toxic to the human body.
Synthesis【2】【3】
1. Synthesis reaction C6H5COCI+NH3+(NH4)2C03→C6H5CONH2
Operation steps: Mix 2 g of ammonium carbonate and 10 mL of concentrated ammonia water, and add 14 g of benzoyl chloride dropwise while stirring without making the reaction temperature exceed 40°C. After adding the ingredients, stir for 0.5 h until the odor of benzoyl chloride is no longer smellable. Filter and wash the filter cake with water. The crude product was recrystallized with 700 mL of water to obtain 12 g of white crystalline benzamide with a melting point of 128 to 129°C.
2. Pyridine method:
Take 0.5 grams of amine and dissolve it in 5cc of anhydrous pyridine. Add 10cc. Anhydrous benzene. Add O.5 cc drop by drop. Benzoyl chloride. Place the mixture in a water bath at 60-70°C and heat it for 30 minutes, then pour 1OOce. in water. Separate the benzene solution and use 10cc of the remaining aqueous solution. Benzene extraction once. Combine the extract and the separated benzene solution, separate and wash with water and 5% sodium carbonate solution, then add a small amount of anhydrous magnesium sulfate to absorb the remaining water. Then filter out the magnesium sulfate with pleated filter paper. Place the filtrate on a boiling water bath and concentrate to 3-4cc. Finally, add about 20cc. Hexane and stirring, the benzamide precipitate can be precipitated.
Benzamide antipsychotics【4】
Sulpiride
Other names: Equilid, thiobenamide, antiemetic, Xiaoyuning.
Pharmacokinetics: Benzamide is absorbed from the gastrointestinal tract, and peak plasma concentration can be reached in 2 hours. 48 hours after oral administration of this product, 30% of the oral dose is excreted in the urine, and part of it is excreted in the feces. t1/2 is 8 to 9 hours. Animal experiments show that this product can penetrate the placenta barrier and enter the human umbilical cord blood circulation. This product is mainly excreted by the kidneys. Can be excreted in breast milk.
Function and use: This product is a benzamide antipsychotic drug. It has antipsychotic effects and strong central antiemetic effects. It can inhibit the excitability of sympathetic nerves and improve gastric blood flow. It is used for schizophrenia, as well as various central vomiting, gastric and duodenal ulcers, dizziness, etc.
Oral administration: to relieve vomiting, 100-200rag each time, 3 times/d.
Adverse reactions:
1. Common symptoms include insomnia, early awakening, headache, irritability, fatigue, loss of appetite, etc.; anticholinergic adverse reactions such as dry mouth, blurred vision, tachycardia, difficulty urinating, and constipation may occur.
2． Extrapyramidal reactions such as tremor, stiffness, salivation, bradykinesia, akathisia, and acute dystonia may occur when the dose is greater than 600 mg per day.
3． It can easily cause an increase in the concentration of prolactin in plasma, and the possible related symptoms are galactorrhea, feminization of gynecomastia, menstrual loss, amenorrhea, and weight gain.
4． Electrocardiogram abnormalities and liver function damage may occur.
5． A small number of patients may experience excitement, agitation, sleep disorders or elevated blood pressure.
6． Long-term use of large amounts of medication can cause tardive dyskinesia.
Tablet: 100 mg.
Notes:
1. The effect appears within two weeks of taking the medicine:
2. Pay attention to liver function and heart condition during medication.
3． Use with caution in patients with hypertension and with caution in patients with pheochromocytoma.
4． Do not engage in operations such as mechanical operation while taking medication.
Drug interactions:
1. Except for clozapine, almost all antipsychotics and central nervous system depressants interact with this product and should be paid full attention to.
2. Concomitant use with lithium may increase the risk of extrapyramidal adverse reactions.
3． Combined use with antacids or sucralfate will affect the absorption of this product.
4． Combined use with dopamine agonists can antagonize the efficacy of this product.
5. Use with drugs that prolong the QT interval or diuretics that cause electrolyte imbalance, especially hypokalemia. Increased risk of developing cardiac arrhythmias.
6. Concomitant use with other antihypertensive drugs may increase the risk of orthostatic hypotension.
Reduction of benzamide【5】
Mix sodium borohydride (1.89g, 0.05 mol), benzamide (1.21g, 0.01mol) and 1,4-dioxane (20mL). Stir and maintain the temperature at about 0°C. Add a mixture of acetic acid (3g, 0.05mol) and 1,4-dioxane (10mL) dropwise within ten minutes. Then heated to reflux for 2 h. Concentrate under reduced pressure and decompose the residue with water. Extract with chloroform. After the chloroform solution is dried, dry hydrogen chloride gas is introduced until salt formation is complete. Evaporate under reduced pressure to obtain crude product. Recrystallize from methanol-diethyl ether to obtain 1.09g (72.2%) of benzylamine hydrochloride, with a melting point of 25l-253℃.
First aid measures
If inhaled, move victim to fresh air. If breathing stops, give artificial respiration. Ask a doctor.
In case of skin contact, wash with soap and plenty of water. Ask a doctor.
In case of eye contact, flush eyes with water as a precaution.
Never give anything by mouth to an unconscious person if swallowed. Rinse mouth with water. Ask a doctor.
Response to leakage:
Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Prevent the generation of dust. Avoid breathing vapors, aerosols or gases. Ensure adequate ventilation. Evacuate personnel to a safe area. Avoid breathing dust.
Environmental precautions: Take steps to prevent further leaks or spills while ensuring safety. Do not allow product to enter drains.
Methods and materials to contain and clean up spills: Collect and dispose of spills without generating dust. Sweep and shovel away. Store in suitable closed disposal containers.
Carcinogenicity
No components of this product at levels greater than or equal to 0.1% have been identified by IARC as possible or definite human carcinogens.
Potential health effects
Inhalation: May be harmful if inhaled and may cause respiratory irritation.
Swallowing: Accidental swallowing is harmful to the human body.
Skin: May be harmful if absorbed through skin and may cause skin irritation.
References
[1] Compiled by Wang Qiongxuan et al., World Organic Intermediates Standard, China Environmental Science Press, July 1991, 1st edition, page 963
[2] Fan Nengyan, Dictionary of Organic Synthesis, Beijing Institute of Technology Press, 1st edition, January 1992, page 187
[3] Compiled by Yu Zhongjian, Systematic Identification Method of Organic Compounds, Commercial Press, 1st edition, October 1946, page 278
[4] Wei Taixing, editor-in-chief Wei Jinghan, Doctor’s Manual of Drugs, Henan Science and Technology Press, 2015.01, page 1118
[5] Li Liangzhu, Lin Yao and others, edited by Principles and Technology of Organic Synthesis, Higher Education Press, 1st edition, May 1992, page 20
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