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339792

Sigma-Aldrich

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

98%

Synonym(s):

Dibutyl squarate

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About This Item

Linear Formula:
[CH3(CH2)3O]2C4(=O)2
CAS Number:
Molecular Weight:
226.27
MDL number:
UNSPSC Code:
12352100
PubChem Substance ID:
NACRES:
NA.22

Assay

98%

form

liquid

refractive index

n20/D 1.494 (lit.)

bp

139 °C/0.5 mmHg (lit.)

density

1.047 g/mL at 25 °C (lit.)

SMILES string

CCCCOC1=C(OCCCC)C(=O)C1=O

InChI

1S/C12H18O4/c1-3-5-7-15-11-9(13)10(14)12(11)16-8-6-4-2/h3-8H2,1-2H3

InChI key

XBRWELTXMQSEIN-UHFFFAOYSA-N

General description

3,4-Dibutoxy-3-cyclobutene-1,2-dione is the dialkyl ester of squaric acid.

Application

3,4-Dibutoxy-3-cyclobutene-1,2-dione was used in the synthesis of novel semisquarylium dye, useful for highly selective Hg2+ sensing in aqueous media. It was also employed in the synthesis of 3-butoxy-4-(1,3,3-trimethyl-2,3-dihydro-1H-2-indolylidenemethyl)-3-cyclobutene-1,2-dione, intermediate for the synthesis of squaryl dyes.

Pictograms

Exclamation mark

Signal Word

Warning

Hazard Statements

Hazard Classifications

Eye Irrit. 2 - Skin Irrit. 2 - Skin Sens. 1 - STOT SE 3

Target Organs

Respiratory system

Storage Class Code

10 - Combustible liquids

WGK

WGK 3

Flash Point(F)

235.4 °F - closed cup

Flash Point(C)

113 °C - closed cup

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

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Aaron E Scott et al.
Toxicology and applied pharmacology, 183(1), 66-70 (2002-09-10)
The ability of chemical or pharmaceutical agents to induce allergic contact dermatitis (ACD) is of major health and regulatory concern. As such, tests to identify their sensitizing capacity, such as the guinea pig maximization test and the more recently developed
Kazumasa Morita et al.
The Journal of dermatology, 29(10), 661-664 (2002-11-16)
Topical immunotherapy is effective for severe alopecia areata. However, there are patients with alopecia areata refractory to topical immunotherapy alone. We tried SADBE (squaric acid dibutylester) topical immunotherapy combined with topical dry ice cryotherapy, carpronium chloride (a parasympathetic nerve stimulant)
Rachid Marhaba et al.
Journal of immunology (Baltimore, Md. : 1950), 179(8), 5071-5081 (2007-10-04)
Induction of a chronic eczema is a most efficient therapy for alopecia areata (AA). We had noted a reduction in regulatory T cells during AA induction and wondered whether regulatory T cells may become recruited or expanded during repeated skin
Cutaneous lymphoid hyperplasia related to squaric acid dibutyl ester.
Eric A Millican et al.
Journal of the American Academy of Dermatology, 65(1), 230-232 (2011-06-18)
Eileen Tan et al.
International journal of dermatology, 41(11), 748-753 (2002-11-28)
Alopecia areata is believed to be an autoimmune condition with a worldwide occurrence. It usually presents as patchy, nonscarring hair loss. There is a paucity of clinical data in Asians. To study the epidemiology, clinical aspects, associations, and treatment of

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