Bromobimane

Bromobimane
Names
	Preferred IUPAC name 3-(Bromomethyl)-2,5,6-trimethyl-1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione
	Other names Bromobimane, mBBr
Identifiers
CAS Number	71418-44-5 ;
3D model (JSmol)	Interactive image;
ChemSpider	102775 ;
PubChem CID	114810;
UNII	V23UK0CYXL ;
CompTox Dashboard (EPA)	DTXSID70221609 ;
	InChI InChI=1S/C10H11BrN2O2/c1-5-7(3)12-8(4-11)6(2)10(15)13(12)9(5)14/h4H2,1-3H3 Key: AHEWZZJEDQVLOP-UHFFFAOYSA-N ; InChI=1/C10H11BrN2O2/c1-5-7(3)12-8(4-11)6(2)10(15)13(12)9(5)14/h4H2,1-3H3 Key: AHEWZZJEDQVLOP-UHFFFAOYAR;
	SMILES O=C1\C(=C(/N2/C(=C(\C(=O)N12)C)CBr)C)C;
Properties
Chemical formula	C10H11BrN2O2
Molar mass	271.114 g·mol−1
Melting point	152 to 154 °C (306 to 309 °F; 425 to 427 K)
Solubility in water	in MeOH, DMF, DMSO
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	alkylating agent
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Bromobimane or monobromobimane is a heterocyclic compound and bimane dye that is used as a reagent in biochemistry. While bromobimane itself is essentially nonfluorescent, it alkylates thiol groups, displacing the bromine and adding the fluorescent tag (λ_emission = 478 nm) to the thiol. Its alkylating properties are comparable to iodoacetamide.^[1]

Synthesis

Bromobimane is prepared from 3,4-dimethyl-2-pyrazolin-5-one (a condensation product of ethyl 2-methylacetoacetate with hydrazine) by chlorination followed by basic treatment; with aqueous K₂CO₃ under heterogeneous conditions, the required syn-bimane, 2,3,5,6-tetramethyl-1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione, is the major product. It can then be selectively brominated to the target bromobimane (with 1 equivalent of Br₂; or dibromobimane, if 2 equivalents of Br₂ are used):^[2]

Bromobimanes are light-sensitive compounds and should be kept refrigerated and protected from light.

References

^ Paul C. Chinn; Vincent Pigiet & Robert C. Fahey (1986). "Determination of thiol proteins using monobromobimane labeling and high-performance liquid chromatographic analysis: Application to Escherichia coli thioredoxin". Analytical Biochemistry. 159 (1): 143–149. doi:10.1016/0003-2697(86)90319-2. PMID 3544950.
^ Kosower, Edward M.; Pazhenchevsky, Barak (1980). "Bimanes. 5. Synthesis and Properties of syn- and anti-1,5-Diazabicyclo[3.3.0]octadienediones (9,10-Dioxabimanes)". Journal of the American Chemical Society. 102 (15): 4983–4993. doi:10.1021/ja00535a028.

[1] Paul C. Chinn; Vincent Pigiet & Robert C. Fahey (1986). "Determination of thiol proteins using monobromobimane labeling and high-performance liquid chromatographic analysis: Application to Escherichia coli thioredoxin". Analytical Biochemistry. 159 (1): 143–149. doi:10.1016/0003-2697(86)90319-2. PMID 3544950.

[Bimanes_synthesis_JACS_1980-2] Kosower, Edward M.; Pazhenchevsky, Barak (1980). "Bimanes. 5. Synthesis and Properties of syn- and anti-1,5-Diazabicyclo[3.3.0]octadienediones (9,10-Dioxabimanes)". Journal of the American Chemical Society. 102 (15): 4983–4993. doi:10.1021/ja00535a028.

[1]

[2]