| Identification | More | [Name]
3,4-Dimethoxy-3-cyclobutene-1,2-dione | [CAS]
5222-73-1 | [Synonyms]
3,4-DIMETHOXY-3-CYCLOBUTENE-1,2-DIONE
3,4-DIMETHOXYCYCLOBUT-3-ENE-1,2-DIONE
DIMETHYL SQUARATE
SQUARIC ACID
SQUARIC ACID DIMETHYL ESTER
3-Cyclobutene-1,2-dione,3,4-dimethoxy-
3,4-DIMETHOXY-3-CYCLOBUTENE-1,2-DIONE, 9 9%
Squaric acid dimethyl ester,(Dimethyl squarate, 3,4-Dimethoxy-3-cyclobutene-1,2-dione)
3,4-DIMETHOXYCYCLOBUTANE-1,2-DIONE
Dimethyl squarate, Squaric acid dimethyl ester
1,2-Dimethoxy-1-cyclobutene-3,4-dione
1,2-Dimethoxycyclobutene-3,4-dione | [EINECS(EC#)]
220-761-4 | [Molecular Formula]
C6H6O4 | [MDL Number]
MFCD00101316 | [Molecular Weight]
142.11 | [MOL File]
5222-73-1.mol |
| Chemical Properties | Back Directory | [Appearance]
white crystalline powder | [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. ]
0-6°C | [solubility ]
DMSO, Methanol (Slightly) | [form ]
Solid | [color ]
Off-White to Pale Brown | [Water Solubility ]
Very soluble in water. | [InChI]
1S/C6H6O4/c1-9-5-3(7)4(8)6(5)10-2/h1-2H3 | [InChIKey]
SZBNZTGCAMLMJY-UHFFFAOYSA-N | [SMILES]
COC1=C(OC)C(=O)C1=O | [CAS DataBase Reference]
5222-73-1(CAS DataBase Reference) | [NIST Chemistry Reference]
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1) |
| Safety Data | Back Directory | [Symbol(GHS) ]
GHS08 | [Signal word ]
Danger | [Hazard statements ]
H317-H334 | [Precautionary statements ]
P261-P280-P342+P311 | [Risk Statements ]
R42/43:May cause sensitization by inhalation and skin contact . | [Safety Statements ]
S22:Do not breathe dust .
S24/25:Avoid contact with skin and eyes .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection . | [WGK Germany ]
3
| [HS Code ]
29145090 | [Storage Class]
11 - Combustible Solids | [Hazard Classifications]
Resp. Sens. 1
Skin Sens. 1 |
| Hazard Information | Back Directory | [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]
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 |
| Spectrum Detail | Back Directory | [Spectrum Detail]
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)MS
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)1HNMR
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)13CNMR
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)IR1
3,4-Dimethoxy-3-cyclobutene-1,2-dione(5222-73-1)IR2
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