dibromomethane

• ChemBase ID: 126964
• Molecular Formular: CH2Br2
• Molecular Mass: 173.83458
• Monoisotopic Mass: 171.85232406
• SMILES: BrCBr
• Canonical SMILES: BrCBr
• InChI: InChI=1S/CH2Br2/c2-1-3/h1H2
• InChIKey: FJBFPHVGVWTDIP-UHFFFAOYSA-N

NAMES AND DATABASE IDS

Names

• IUPAC name: dibromomethane
• IUPAC Traditional name: dibromomethane
• Synonyms: Methyl dibromide; Methylene bromide; Methylene dibromide; Refrigerant-30B2; Dibromomethane; Dibromomethane; Dibromomethane solution; 甲叉二溴; 二溴甲烷; 二溴甲烷 溶液

Database IDs

• CAS Number: 74-95-3
• EC Number: 200-659-6; 200-824-2
• MDL Number: MFCD00000168
• Beilstein Number: 969143
• Merck Index: 146061
• PubChem SID: 24893828; 162221288; 24854398; 24884902; 24871436
• PubChem CID: 3024
• CHEBI ID: 47077
• Chemspider ID: 2916
• Gmelin ID: 25649
• MeSH Name: methylene+bromide
• Wikipedia Title: Dibromomethane

CALCULATED PROPERTIES

• H Acceptors: 0
• H Donor: 0
• LogD (pH = 5.5): 1.0393913
• LogD (pH = 7.4): 1.0393913
• Log P: 1.0393913
• Molar Refractivity: 22.0715 cm^3
• Polarizability: 8.78044 Å^3
• Polar Surface Area: 0.0 Å^2
• Rotatable Bonds: 0
• Lipinski's Rule of Five: true

PROPERTIES

Physical Property

• Solubility: 12.5 g L^-1 (at 20 °C) in water
• Apperance: Colorless liquid
• Melting Point: -52 °C(lit.); -52.70°C (220.45K); -53°C
• Boiling Point: 95.85 - 97.85°C (369 - 371 K); 96-98 °C(lit.); 96-98°C
• Flash Point: 11 °C; 51.8 °F
• Density: 2.477 g mL^-1; 2.477 g/mL at 25 °C(lit.); 2.495
• Refractive Index: 1.541; 1.5410; n20/D 1.541; n20/D 1.541(lit.)
• Vapor Pressure: 34.9 mmHg ( 20 °C); 4.65 kPa (at 20.0 °C)
• Vapor Density: 6.05 (vs air)
• Henry Constant: 9.3 μmol Pa^-1 kg^-1
• Heat Capacity: 104.1 J K^-1 mol^-1

Safety Information

• RTECS: PA7350000
• European Hazard Symbols: Flammable (F); Toxic (T); X; Harmful (Xn)
• UN Number: 1230; 2664; UN2664
• German water hazard class: 1; 2
• Hazard Class: 3; 6.1
• Packing Group: 2; 3; III
• Risk Statements: 11-23/24/25-39/23/24/25; 20-52/53; R20, R52/53
• Safety Statements: 24-61; 7-16-36/37-45; S2, S24
• TSCA Listed: 是
• EU Index: 602-003-00-8
• GHS Pictograms: GHS exclamation mark; GHS02; GHS06; GHS07; GHS08
• GHS Signal Word: WARNING; Danger; Warning
• NFPA704:
  

  0

  2

  0
• LD50: >4 g kg^-1 (dermal, rabbit); 1 g kg^-1 (oral, rabbit); 3.738 g kg^-1 (subcutaneous, mouse)
• GHS Hazard statements: 332, 412; H225-H301-H311-H331-H370; H332-H412
• GHS Precautionary statements: 273; P210-P260-P280-P301 + P310-P311; P261-P273-P271-P304+P340-P312-P501A; P273
• Personal Protective Equipment: Eyeshields, Faceshields, full-face respirator (US), Gloves, multi-purpose combination respirator cartridge (US), type ABEK (EN14387) respirator filter
• RID/ADR: UN 1230 3/PG 2; UN 2664 6.1/PG 2; UN 2664 6.1/PG 3
• Storage Temperature: 2-8°C

Product Information

• Purity: ≥98.5% (GC); ≥99%; 99%; 99%, stab. with 50ppm BHT
• Concentration: 2000 μg/mL in methanol; 5000 μg/mL in methanol
• Grade: analytical standard; puriss.
• Packaging: ampule of 1 mL; ampule of 1000 mg
• Empirical Formula (Hill Notation): CH2Br2

DETAILS

Sigma Aldrich - 239992

Packaging
50 mL in glass bottle

Sigma Aldrich - D41686

Packaging
2 L in glass bottle
500 mL in glass bottle

Sigma Aldrich - 66730

Other Notes
Reagent, together with Zn and TiCl4, for the methylenation of carbonyl compounds1

REFERENCES

• For in situ formation of dibromomethyllithium by reaction with lithiated 2,2,6,6-Tetramethylpiperidine, A18712, and use in a one-pot ester homologation sequence, safer and more convenient than the classical Arndt-Eistert (diazomethane) method, see: Org. Synth. Coll., 9, 426 (1998):
  
• Reaction with NaHMDS generates monobromocarbene, which reacts with alkenes to give bromocyclopropanes: Synthesis, 201 (1972). It can also be generated by reaction with diethylzinc in the presence of O₂: J. Chem. Soc., Chem. Commun., 364 (1975).
• The Simmons-Smith reaction (see Diiodomethane, A15457) may be extended to the use of dibromomethane in the cyclopropanation of simple electron-deficient alkenes, using a reducing agent prepared from NiBr₂, NaI and Zn: Bull. Chem. Soc. Jpn., 56, 1025 (1983); or with CuCl/Zn: J. Org. Chem., 55, 2491 (1990).
• With TiCl₄/Zn, methylenation of ketones occurs, as a useful mild alternative to the Wittig reaction: Tetrahedron Lett., 23, 4293 (1982); Org. Synth. Coll., 8, 386 (1993). For a variant using Zn, CuCl and catalytic TiCl₄, see: J. Org. Chem., 54, 2388 (1989).
• With alcohols, formaldehyde acetals can be formed under phase-transfer conditions: Bull. Chem. Soc. Jpn., 66, 2149 (1993). Diols give methylenedioxy derivatives, which are components of many biologically-important molecules. For use of KF in DMF as base in the methylenation of catechols, see: Tetrahedron Lett., 3361 (1976). KOH in DMSO has been recommended for the methylenation of base-stable carbohydrate diols: Synthesis, 421 (1982). For the methylenation of ribonucleosides under phase-transfer conditions, see: Synthesis, 715 (1981).