ChemicalBook CAS DataBase List 4,5-DIMETHOXY-ISATOIC ANHYDRIDE

4,5-DIMETHOXY-ISATOIC ANHYDRIDE synthesis

9synthesis methods

Product Name:4,5-DIMETHOXY-ISATOIC ANHYDRIDE
CAS Number:20197-92-6
Molecular formula:C10H9NO5
Molecular Weight:223.18

501-53-1

5653-40-7

20197-92-6

The general procedure for the synthesis of 6,7-dimethoxy-2H-benzo[d][1,3]oxazine-2,4(1H)-diones from benzyl chloroformate and 2-amino-4,5-dimethoxybenzoic acid is as follows: 1. 2-Amino-4,5-dimethoxybenzoic acid (25 g, 0.13 mol) was dissolved in tetrahydrofuran (THF, 400 mL). 2. Benzyl chloroformate (54 mL, 0.38 mol) was added slowly with vigorous stirring. 3. The reaction mixture was refluxed overnight, followed by evaporation to dryness and further removal of residual solvent under vacuum. 4. Ether (425 mL) was added to the residue followed by phosphorus tribromide (PBr3, 11.88 mL, 0.13 mol). 5. The mixture was refluxed for 48 hours, after which the reaction mixture was filtered and the solid was washed with ether (3 × 150 mL). 6. The residue was redissolved in ether, stirred for 1 h and then filtered, washed and dried to give 27 g of a white powdery product, 6,7-dimethoxy-2H-benzo[d][1,3]oxazine-2,4(1H)-dione. Yield: 96%. 1H NMR (DMSO-d6, 200 MHz): δ 3.82 (s, 3H, OCH3), 3.88 (s, 3H, OCH3), 6.66 (s, 1H, Ar), 7.27 (s, 1H, Ar), 11.58 (s, 1H, exchangeable NH).

32315-10-9 Synthesis

32315-10-9
435 suppliers
$10.00/1g

5653-40-7 Synthesis

5653-40-7
284 suppliers
$12.50/5 g

20197-92-6
94 suppliers
$15.00/250mg

Yield: 99%

Reaction Conditions:

in tetrahydrofuran at 0; for 5 h;Inert atmosphere;Large scale;

Steps:

4
Under electromagnetic stirring and ice-water bath cooling, respectively add 1d (2000mg, 10.15mmol) and tetrahydrofuran (35mL) to a 150mL round bottom flask, wait for the reaction system to cool, and then slowly add triphosgene (1021mg, 3.45mmol).Under N2 protection, stir for 5h. After the reaction is over, the solvent is removed under reduced pressure, an appropriate amount of petroleum ether is added and sonicated, the precipitated solid is fully suspended in the petroleum ether, and filtered with suction.After drying, 2230 mg of brown solid of compound 2d was obtained (yield 99%).

References:

Guangxi Normal University;Su Guifa;Wang Wang;Pang Li;Xie Ying;Pan Chengxue;Mo Dongliang CN111825679, 2020, A Location in patent:Paragraph 0057-0059

501-53-1
410 suppliers
$10.00/1g

5653-40-7 Synthesis

5653-40-7
284 suppliers
$12.50/5 g

20197-92-6
94 suppliers
$15.00/250mg

References