Product standards and product uses of phenylacetic acid

The molecular formula of phenylacetic acid is C ₈ H ₈ O ₂ , the molecular weight is 136.
15, and the structural formula is

1.
Product performance

Colorless flake crystal; melting point 76.
5℃, boiling point 265.
5℃, 144.
5℃/1.
60kPa, 65～70℃/0.
013kPa, relative density (d ₄ ⁷⁷ ) 1.
091; soluble in hot water, soluble in alcohol, ether, chloroform , Carbon tetrachloride , slightly soluble in water; natural products found in roses, orange blossoms, Japanese mint, etc.
; acidic; mildly irritating to the skin, low toxicity
.

2.
Production principle

Phenylacetonitrile is hydrolyzed under acidic conditions to get phenylacetic acid
.

3.
Process flow

4.
Technical formula (kg/t)

5.
Main equipment

Hydrolysis reactor, residual liquid tank, dehydrated gold, storage tank
.

6.
Production process

Add 496kg of 70% sulfuric acid into the hydrolysis reactor, stir and heat to 100°C
.
Then slowly add benzyl acetonitrile dropwise, after dropping 472kg in 5h, the temperature is raised to 130°C, the temperature is kept and the reaction is continued for 8h, and then 18kg of water is added

7.
Laboratory preparation method

In a three-necked round-bottom beaker, add 59 g of benzyl acetonitrile, 75 mL of water and 25 mL of acetic acid, add 61 mL of concentrated sulfuric acid under stirring, and heat to reflux for 2 hours
.
Add 340mL of cold water to dilute with stirring, cool to room temperature, crystallize, filter with suction, and wash the filter cake with water

8.
Product Standard

9.
Quality inspection

1) Assay

After drying the phenylacetic acid sample in a sulfuric acid dryer for 3 hours, accurately weigh 0.
5 g, dissolve it with neutral 50% ethanol, and then use phenolphthalein as an indicator to titrate to pink with 0.
1 mol/L NaOH solution
.

In the formula: c—— concentration of sodium hydroxide standard solution, mol/L;

V——The volume of sodium hydroxide standard solution consumed by the sample, mL;

G——The mass of the sample, g
.

2) Melting range measurement

According to GB/T617-2006 "General Method for the Determination of the Melting Point of Chemical Reagents"
.

10.
Product use

It is used as a synthetic intermediate for medicines, pesticides, and spices; it is also a raw material for flavors, pesticides, and plant growth regulators
.

11.
Safety measures

(1) The raw material benzyl acetonitrile is poisonous and irritates the eyes and skin.
The maximum allowable concentration in the production site is 0.
008mg/L
.
The production equipment should be closed, the workshop should be well ventilated, and the operators should wear protective equipment

(2) Packed in iron drum lined with plastic bag and stored in a cool and dry place

Related links: Product performance and production process of m-nitrobenzoic acid