ChemicalBook CAS DataBase List 2H-1,3-Benzoxazine-2,4(3H)-dione

2H-1,3-Benzoxazine-2,4(3H)-dione synthesis

13synthesis methods

Product Name:2H-1,3-Benzoxazine-2,4(3H)-dione
CAS Number:2037-95-8
Molecular formula:C8H5NO3
Molecular Weight:163.13

2H-1,3-Benzoxazine-2,4(3H)-dione was prepared according to the procedure of Hoback, Crum and Carroll. To a solution of 411 g. (3. 0 moles) salicylamide in 483 ml. (6.0 moles) of anhydrous pyridine at 0℃ was added slowly with stirring 572 ml. (6.0 moles) of ethyl chlorocarbonate. The resulting orange solution was refluxed for 5 hr. and poured into 2L of ice water. The filtered product was washed twice with 0.5L of water and recrystallized three times from acetone-ethanol (50: 50), giving white needles 2H-1,3-Benzoxazine-2,4(3H)-dione (83% yield), m.p. 227.5-228.5° (lit. 12), m.p. 227-228°, which gave no coloration with ethanolic ferric chloride[1].

530-62-1 Synthesis

530-62-1
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65-45-2 Synthesis

65-45-2
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$5.00/25g

2037-95-8
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$5.00/25mg

Yield:2037-95-8 97.9%

Reaction Conditions:

in N,N-dimethyl-formamide at 0 - 20;

Steps:

1 Example 1 Preparation of Compound 1 (2H-Benzo[e][1,3]oxazine-2,4(3H)-dione)

Add 20.0 g (0.146 mol) and 80 ml of salicylamide to a 250 ml reaction flask with a magnet and a thermometer.DMF, stirring and cooling to 0 to 5 ° C, 28.4 g (0.175 mol) of N'N-carbonyldiimidazole was added in portions, and the temperature was controlled at 0 to 5 °C. Then, the reaction was carried out at room temperature for 2 to 3 hours, 240 ml of purified water was added, pH was adjusted to 1 to 3 with 6 M hydrochloric acid aqueous solution, stirring was continued for 30 min, and filtration was carried out. The filter cake was rinsed with purified water, and the filter cake was placed in a blast drying oven at 45 . Drying at 50 ° C for 16 h gave 23.3 g of a white solid.The yield was 97.9%.

References:

CN108689876,2018,A Location in patent:Paragraph 0018; 0024-0025