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

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

Product Name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
CAS No.
5222-73-1
Chemical Name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Synonyms
3,4-DIMETHOXYCYCLOBUT-3-ENE-1,2-DIONE;DIMETHYL SQUARATE;diMethoxycyclobut-3-ene-1,2-dione;3,4-Dimethoxy-3-cycl;Squaric acid dimethyl e;SQUARIC ACID DIMETHYL ESTER;3,4-DIMETHOXYCYCLOBUTANE-1,2-DIONE;1,2-Dimethoxycyclobutene-3,4-dione;3,4-DIMETHOXY-3-CYCLOBUTENE-1,2-DIONE;1,2-Dimethoxy-1-cyclobutene-3,4-dione
CBNumber
CB3165164
Molecular Formula
C6H6O4
Formula Weight
142.11
MOL File
5222-73-1.mol
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3,4-Dimethoxy-3-cyclobutene-1,2-dione Property

Melting point:
55-57 °C (lit.)
Boiling point:
219.65°C (rough estimate)
Density 
1.3863 (rough estimate)
refractive index 
1.5800 (estimate)
storage temp. 
2-8°C
solubility 
DMSO, Methanol (Slightly)
form 
Solid
color 
Off-White to Pale Brown
Water Solubility 
Very soluble in water.
InChIKey
SZBNZTGCAMLMJY-UHFFFAOYSA-N
CAS DataBase Reference
5222-73-1(CAS DataBase Reference)
NIST Chemistry Reference
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)
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Safety

Risk Statements 
42/43
Safety Statements 
22-24/25-26-36/37/39
WGK Germany 
3
HS Code 
29145090
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Hazard and Precautionary Statements (GHS)

Symbol(GHS)
Signal word
Danger
Hazard statements

H317May cause an allergic skin reaction

H334May cause allergy or asthma symptoms or breathing difficulties if inhaled

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P342+P311IF experiencing respiratory symptoms: call a POISON CENTER or doctor/physician.

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N-Bromosuccinimide Price

Sigma-Aldrich
Product number
377406
Product name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Purity
99%
Packaging
1g
Price
$28.3
Updated
2025/07/31
Sigma-Aldrich
Product number
377406
Product name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Purity
99%
Packaging
5g
Price
$107
Updated
2025/07/31
TCI Chemical
Product number
D2099
Product name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Purity
>98.0%(GC)
Packaging
1g
Price
$44
Updated
2025/07/31
TCI Chemical
Product number
D2099
Product name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Purity
>98.0%(GC)
Packaging
5g
Price
$134
Updated
2025/07/31
TCI Chemical
Product number
D2099
Product name
3,4-Dimethoxy-3-cyclobutene-1,2-dione
Purity
>98.0%(GC)
Packaging
25g
Price
$459
Updated
2025/07/31
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3,4-Dimethoxy-3-cyclobutene-1,2-dione Chemical Properties,Usage,Production

Chemical Properties

white crystalline powder

Uses

3,4-Dimethoxy-3-cyclobutene-1,2-dione (Dimethyl squarate) finds it uses in the synthesis of chiral squaramides, highly enantioselective catalyst for the Friedel-Crafts reactions of indoles, 3-(hydroxyamino)-4-methoxy-3-cyclobutene-1,2-dione, squarate derivatives of the O-SP-core antigens, methyl squarate derivative of the Ogawa O-SP-core antigen, o-quinodimethanes, benzocyclobutenes, quinones. It is employed as a starting material in the preparation of o-quinodimethanes, benzocyclobutenes, and quinones.

General Description

3,4-Dimethoxy-3-cyclobutene-1,2-dione (Dimethyl squarate) is a cyclobutene derivative. It reacts with hydroxylamine derivatives to afford 3-hydroxyamino-4-methoxy-3-cyclobutene-1,2-diones.

Synthesis

2892-51-5

149-73-5

5222-73-1

3,4-Dimethoxy-3-cyclobutene-1,2-dione (compound 30) was synthesized using a modified Liu et al. method [7]. The procedure was as follows: 3,4-dihydroxy-3-cyclobutene-1,2-dione (squaric acid, 2.053 g, 18 mmol) was dissolved in anhydrous methanol (18 mL), followed by addition of trimethyl orthoformate (4 mL, 36.5 mmol) to the solution. The reaction mixture was refluxed at 56 °C for 24 hours. Upon completion of the reaction, the crude product was concentrated under reduced pressure. The resulting light yellow solid was dissolved in dichloromethane and purified by silica gel column chromatography (eluent ratio of ethyl acetate: hexane = 1:2) to afford 3,4-dimethoxycyclobut-3-ene-1,2-dione (2.29 g, 89.4% yield) as a final white solid. The melting point of the compound is 55-57 °C (literature value 56-58 °C) [7,8]. NMR hydrogen spectrum (300 MHz, CD2Cl2) δ 4.34 (6H, s, OCH3); NMR carbon spectrum (75 MHz, CD3OD) δ 189.35 (C2, C=O), 189.35 (C1, C=O), 184.35 (C3), 184.35 (C4), 60.29 (OCH3), 60.29 ( OCH3). Low resolution mass spectra (EI): m/z 142.03 (100%), 114.03 (18%), 99.01 (16%), 86.01 (54%), 67.99 (8%), 56.25 (7%).

References

[1] Bioorganic and Medicinal Chemistry Letters, 2017, vol. 27, # 2, p. 282 - 287
[2] Organic Syntheses, 1999, vol. 76, p. 189 - 189
[3] Chemistry - A European Journal, 2011, vol. 17, # 49, p. 13698 - 13705
[4] Chemistry - A European Journal, 2017, vol. 23, # 47, p. 11234 - 11238
[5] Chemical Communications, 2018, vol. 54, # 26, p. 3231 - 3234

3,4-Dimethoxy-3-cyclobutene-1,2-dione Preparation Products And Raw materials

Raw materials

Preparation Products

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View Lastest Price from 3,4-Dimethoxy-3-cyclobutene-1,2-dione manufacturers

ZHENGZHOU JIUYI TIME NEW MATERIALS CO,.LTD
Product
Dimethyl squarate 5222-73-1
Price
US $2.00-5.00/KG
Min. Order
0.1KG
Purity
99%
Supply Ability
g-kg-tons
Release date
2025-07-10
Henan Aochuang Chemical Co.,Ltd.
Product
3,4-Dimethoxy-3-cyclobutene-1,2-dione 5222-73-1
Price
US $0.00-0.00/KG
Min. Order
1KG
Purity
98%
Supply Ability
1ton
Release date
2022-09-19
Career Henan Chemical Co
Product
3,4-Dimethoxy-3-cyclobutene-1,2-dione 5222-73-1
Price
US $7.00/kg
Min. Order
1kg
Purity
99%
Supply Ability
100kg
Release date
2018-12-14

5222-73-1, 3,4-Dimethoxy-3-cyclobutene-1,2-dioneRelated Search:

Dimethyl sulfoxide 1,1-Dimethoxyethane Diphenyldimethoxysilane Dimethyldimethoxysilane Dacthal (-)-Dimethyl D-tartrate Dimethyl malonate Dimethyl ether Dimethyl acetylenedicarboxylate Dimethyl fumarate 3-SULFOLENE Dimethyl sebacate N,N-Dimethylformamide Dimethyl malate DIMETHYL PHOSPHATE Dimethyl suberate Dimethyl sulfate Dimethyl carbonate

  • DIMETHYL SQUARATE
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  • SQUARIC ACID DIMETHYL ESTER
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  • 3,4-DIMETHOXYCYCLOBUT-3-ENE-1,2-DIONE
  • Squaric acid dimethyl ester,(Dimethyl squarate, 3,4-Dimethoxy-3-cyclobutene-1,2-dione)
  • 3,4-DIMETHOXYCYCLOBUTANE-1,2-DIONE
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  • 1,2-Dimethoxycyclobutene-3,4-dione
  • 3,4-DIMETHOXY-3-CYCLOBUTENE-1,2-DIONE, 9 9%
  • 3,4-Dimethoxy-3-cycl
  • 3.4-diMethoxycyclobutane-1.2-dione. DiMethyl squarate
  • 8,9-dimethoxy-2-[[2-(4-morpholinyl)ethylamino]-oxomethyl]-5,6-dihydropyrrolo[2,1-a]isoquinoline-3-carboxylic acid
  • 3,4-Dimethoxy-3-cyclobutene-1,2-dione&gt
  • 5222-73-1
  • CH3O2C4O2
  • C6H6O4
  • Ketones
  • Organic Building Blocks
  • C3 to C6
  • Simple 4-Membered Ring Compounds
  • Cyclobutanes & Cyclobutenes
  • Carbonyl Compounds
  • Building Blocks
  • Cyclobutanes & Cyclobutenes
  • Simple 4-Membered Ring Compounds
  • Ring Systems
  • Aluminium foil bag/Fluoride bottle or on your request
  • Pyrimidines