ChemicalBook CAS DataBase List 4-Hydroxybenzylamine

4-Hydroxybenzylamine synthesis

14synthesis methods

Product Name:4-Hydroxybenzylamine
CAS Number:696-60-6
Molecular formula:C7H9NO
Molecular Weight:123.15

Synthesis of 4-Hydroxybenzylamine:Ammonia is passed into 500 ml of ethanol at 10° C. until saturation is reached, 122.1 g=1 mole of p-hydroxybenzaldehyde, 20 g of Raney nickel and 0.1 ml of concentrated sulfuric acid are added and the mixture is stirred in an autoclave for 6 hours at room temperature and under a hydrogen pressure of 100 atmospheres. After releasing the pressure, the catalyst is filtered off and the filtrate is boiled up with active charcoal, filtered and concentrated. The residue is recrystallized from a mixture of ethanol and ether. This gives 104 g (85% of theory), melting point: 104° C.
Literature source US04391805

2393-23-9 Synthesis

2393-23-9
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$20.00/25g

696-60-6
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$9.00/250mg

Yield:696-60-6 92.5%

Reaction Conditions:

Stage #1:4-methoxy-benzylamine with hydrogen bromide in water at 120 - 126;
Stage #2: with sodium hydroxide in waterCooling;

Steps:

3-4 Example 3: Synthesis of 4-hydroxybenzylamine
_{In 1L with thermometer, dropping funnel, adjustable power heating jacket, 970.9 g (3.0 mol) of 25% hydrobromic acid was put into the reactor of the agitator and distillation device, Under stirring, 103.7 g (0.7558 mol) of 4-methoxybenzylamine was slowly added dropwise using a dropping funnel, Drop by drop, Raise the excess water to remove excess water until the distillation temperature reaches above 120°C (in this case, the temperature in the reactor reaches above 126 °C ), Reduce the heating rate, make it into a reflux state or distill at a very slow rate, Keep the temperature in the reactor above 126 °C , The generated gas is absorbed by solvent or recovered by freezing method to protect the environment, When no more gas is observed, increase the heating rate again and continue the distillation. Recover excess hydrobromic acid until the temperature in the reactor reaches above 132 °C , slightly colder, Add 200 milliliters of water, dropwise add a pre-cooled mass concentration of 40% sodium hydroxide aqueous solution under water cooling, Precipitate and drop again until the precipitate completely disappears, extract and wash twice with 50 ml of toluene, The organic phase recovers toluene, the water phase is adjusted with 30.0% hydrochloric acid under ice-cooling to pH: 9-10, stirred for crystallization, Filtration with suction, the filter cake was washed with 240 ml of water and then vacuum dried, It is the state when the absolute pressure is less than 10 mm Hg. After rotating and vacuum drying at room temperature for 2 hours, Then increase it to 80 according to the heating rate of 10 / hour, and bake it to constant weight to get the finished product. Total: 86.9 g, water content determined by Karl Fischer method: 0.2%, molar yield: 92.5%.}

References:

Taizhou Chuangyuan Industry Co., Ltd.;Xu Changping;Jia Yanrong CN110803996, 2020, A Location in patent:Paragraph 0046-0052

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123-08-0 Synthesis