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ChemicalBook CAS DataBase List 3,4-Dimethoxy-3-cyclobutene-1,2-dione
5222-73-1

3,4-Dimethoxy-3-cyclobutene-1,2-dione synthesis

9synthesis methods
-

Yield:5222-73-1 87%

Reaction Conditions:

with sulfuric acid for 24 h;Reflux;

Steps:

2.2.1. Obtaining of 3,4-dimethoxy-3-cyclobutene-1,2-dione (4)
A solution of 0.30 g (2.6 mmol) of squaric acid (1) and 0.80 g(4.1 mmol) of concentrated sulfuric acid in 25 mL of anhydrous methanolin a round-bottomed flask equipped with a reflux condenser washeated until reflux for 24 h. After the reaction was complete, the solutionwas cooled, neutralized with saturated sodium bicarbonate solutionand extracted with 3 × 50 mL of dichloromethane. The organicphase was then dried with anhydrous magnesium sulfate, filtered andevaporated to afford 0.32 g (87%) of a yellow oil. IR (ATR, cm-1): 2996(νc-H), 1809 (νC=O), 1638 (νC=C), 1266 (νC-O), 735 (δC-H)·1H NMR(400 MHz, CDCl3-d1) δ 4.37. 13C NMR (400 MHz, CDCl3-d1) δ 61.22,184.67, 189.39.

References:

ávila-Costa, Marina;Donnici, Claudio L.;dos Santos, Jordana Dias;Diniz, Renata;Barros-Barbosa, Alexandre;Cuin, Alexandre;de Oliveira, Luiz Fernando Cappa [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy,2019,vol. 223,art. no. 117354]

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