4-BROMO PHTHALIC ANHYDRUS synthesis
- Product Name:4-BROMO PHTHALIC ANHYDRUS
- CAS Number:86-90-8
- Molecular formula:C8H3BrO3
- Molecular Weight:227.01
85-44-9
86-90-8
To a suspension of phthalic anhydride (1) (22 g, 148.5 mmol, 1.0 eq.) in water (150 mL) was slowly added sodium hydroxide (12 g, 300.0 mmol, 2.0 eq.) and pure bromine (8.5 mL, 165.9 mmol, 1.1 eq.). The reaction mixture was stirred at 90 °C for 12 hours. Upon completion of the reaction, the mixture was cooled to 0 °C and filtered to collect a pale yellow solid. After washing the solid with cold water (50 mL), it was dissolved in sulfur dioxide (60 mL) and the mixture was heated to reflux for 5 hours. The reaction mixture was concentrated and dichloromethane (200 mL) was added to the residue and stirred at room temperature for 2 hours. After filtration, the filtrate was concentrated to give 5-bromoisobenzofuran-1,3-dione (2) (20 g, 71% yield) as a yellow solid.1H NMR (400 MHz, CDCl3) δ 8.16-8.17 (m, 1H), 8.06-8.07 (m, 1H), 7.89-7.90 (m, 1H).
85-44-9
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$9.00/5g
86-90-8
290 suppliers
$7.00/5g
Yield:86-90-8 85.4%
Reaction Conditions:
with N-benzyl-N,N,N-triethylammonium chloride;bromine;sodium hydroxide in water at 45 - 80; for 11.7 h;Catalytic behavior;Reagent/catalyst;Temperature;
Steps:
4 Example 4,
The present invention provides a process for the preparation of 4-bromo-phthalic anhydride,First, 11.3 g of sodium hydroxide was dissolved in 50 g of water,20 g of phthalic anhydride was added and stirred well, followed by the addition of 0.5 g of benzyltrimethylammonium chloride catalyst and stirring was continued.The reaction was then carried out in three stages of temperature control and three times addition of reactants,The first temperature control temperature is 45 ,The mass of bromine added was 11.5 g and the reaction time was 1.7 hours.The second paragraph temperature control temperature is 70 ,The mass of the added bromine was 10.8 g,Reaction time is 5 hours;The third temperature control temperature is 80 ,3g of sodium hydroxide was added and 10 g of bromine was added thereto to continue the reaction for 5 hours.At the end of the reaction, 15 g of fuming sulfuric acid was added to the product with a mass fraction of 20%Heating to 96 ° C for acidification,After the acidification was completed, the mixture was cooled to 25 ° C,Then, 15 g of an aqueous solution of sodium bisulfite having a mass fraction of 10% was added to remove the excess bromine.Ethyl acetate was then added for extraction,After standing for 8 minutes, the organic layer was taken,And the organic layer is distilled to remove the organic solvent,The distillation temperature was 110 ° C,The temperature was then raised to 200 ° C to give crude 4-bromophthalic anhydride.Then 4-bromo-phthalic anhydride in the vacuum of 0.095MPa vacuum distillation under the conditions,And the fractions having a temperature of about 215 ° C were collected,To obtain 4-bromo-phthalic anhydride product.
References:
CN105399712,2016,A Location in patent:Paragraph 0025
6968-28-1
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86-90-8
290 suppliers
$7.00/5g
6941-75-9
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$5.00/1g
86-90-8
290 suppliers
$7.00/5g
583-71-1
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86-90-8
290 suppliers
$7.00/5g