Tert-Butyl Methyl Ether CAS#1634-04-4
Methyl tert-butyl ether (MTBE) is a clear liquid carrying a sharp, disagreeable smell. It is synthesized from raw materials including isobutylene and methanol. Starting from the 1980s, MTBE has been adopted as an additive for unleaded gasoline to enable cleaner combustion with reduced environmental footprint.
MTBE also finds a unique use for gallstone dissolution. For this therapeutic purpose, MTBE is infused straight into the gallbladder via specially placed catheters under surgical intervention.
tert-Butyl methyl ether Chemical Properties
| Melting point | -110 °C |
| Boiling point | 55-56 °C(lit.) |
| density | 0.7404 |
| vapor density | 3.1 (vs air) |
| vapor pressure | 4.05 psi ( 20 °C) |
| refractive index | n20/D 1.369(lit.) |
| Fp | -27 °F |
| storage temp. | Store at +2°C to +25°C. |
| solubility | 42g/l |
| form | Powder or Needles |
| color | APHA: ≤10 |
| Specific Gravity | 0.74 |
| Odor | Characteristic ethereal odor |
| Relative polarity | 0.124 |
| explosive limit | 1.5-8.5%(V) |
| Water Solubility | 51 g/L (20 ºC) |
| FreezingPoint | -108.6℃ |
| λmax | λ: 210 nm Amax: 1.0 |
| λ: 225 nm Amax: 0.50 | |
| λ: 250 nm Amax: 0.10 | |
| λ: 300-400 nm Amax: 0.005 | |
| Merck | 146032 |
| BRN | 1730942 |
| Exposure limits | ACGIH: TWA 50 ppm |
| Dielectric constant | 4.5 |
| Stability: | Stable, but may form explosive peroxides in contact with air. Extremely flammable - note low flash point. Incompatible with strong oxidizing agents. |
| InChIKey | BZLVMXJERCGZMT-UHFFFAOYSA-N |
| LogP | 1.06 at 20℃ |
| CAS DataBase Reference | 1634-04-4(CAS DataBase Reference) |
| IARC | 3 (Vol. 73) 1999 |
| NIST Chemistry Reference | Propane, 2-methoxy-2-methyl-(1634-04-4) |
| EPA Substance Registry System | Methyl tert-butyl ether (1634-04-4) |
| Hazard Codes | Xn,F,Xi,T |
| Risk Statements | 36/37/38-40-38-11-39/23/24/25-23/24/25 |
| Safety Statements | 9-16-24-45-36/37-7 |
| RIDADR | UN 2398 3/PG 2 |
| WGK Germany | 3 |
| RTECS | KN5250000 |
| F | 46091 |
| Autoignition Temperature | 705 °F |
| TSCA | Yes |
| HS Code | 2909 19 90 |
| HazardClass | 3 |
| PackingGroup | II |
| Hazardous Substances Data | 1634-04-4(Hazardous Substances Data) |
| Toxicity | . LC50 in mice (15 min): 1.6 mmol/liter of atmosphere (Marsh) |
Product Usage
Prior to 2005, methyl tert-butyl ether (MTBE) served on a large scale as an additive for unleaded gasoline within the United States. Besides, it acts as a starting material for isobutene manufacturing and functions as a mobile phase solvent for chromatography, especially for high-pressure liquid chromatography analysis.
Beyond that, MTBE has established pharmaceutical uses. It can be delivered into the gallbladder to dissolve gallstones (ATSDR, 1996). This ether compound also occupies a position in petrochemical workflows. Under acidic catalysts and elevated temperatures exceeding its synthesis conditions, MTBE can undergo cleavage via the reverse synthesis reaction to yield isobutene and methanol.
