Sodium bis(2-methoxyethoxy)aluminumhydride

Sodium bis(2-methoxyethoxy)aluminumhydride

Names
IUPAC name Sodium bis(2-methoxyethoxy)aluminumhydride
Other names Red-Al, Synhydrid, Vitride
Identifiers
CAS Number	22722-98-1
Abbreviations	SMEAH
ChemSpider	21169529
Jmol 3D model	Interactive image Interactive image
PubChem	16684438
InChI InChI=1S/2C3H7O2.Al.Na.2H/c2*1-5-3-2-4;;;;/h2*2-3H2,1H3;;;;/q2*-1;2*+1;; Key: XJIQVZMZXHEYOY-UHFFFAOYSA-N
SMILES [Na+].COCCO[AlH2-]OCCOC [H][Al-](OCCOC)([H])OCCOC.[Na+]
Properties
Chemical formula	C6H16AlNaO4
Molar mass	202.16 g·mol^−1
Appearance	Transparent crystals
Density	1.036 g/mL (>60% solution)
Viscosity	65.1 cps (70% solution)
Hazards
Main hazards	Unstable toward water
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium bis(2-methoxyethoxy)aluminumhydride (trade names Red-Al, Synhydrid, Vitride) is an organoaluminium compound with the formula NaAlH₂(OCH₂CH₂OCH₃)₂. The trade name Red-Al refers to its being a reducing aluminium compound. It is used predominantly as a reducing agent in organic synthesis. The compound features a tetrahedral aluminium center attached to two hydride and two alkoxide groups, the latter derived from 2-methoxyethanol. Commercial solutions are colourless/pale yellow and viscous. At low temperatures, the solution solidifies to a glassy pulverizable substance. No sharp melting point was found.

Sodium bis(2-methoxyethoxy)aluminumhydride is a versatile hydride reducing agent. It readily converts aldehydes, ketones, carboxylic acids, esters, acyl halides, and anhydrides to primary alcohols. The cyclic compounds such a lactones and epoxides are reduced to diols. Nitrogen derivates such a amides, nitriles, imines, and most other organonitrogen compounds are reduced to the corresponding amines. Nitroarenes can be converted to azoxyarenes, azoarenes, or hydroazoarenes, depending on the reaction conditions.^[1]

Some common functional group reductions using sodium bis(2-methoxyethoxy)aluminumhydride can be found below:

Comparison with lithium aluminium hydride

As a reagent, sodium bis(2-methoxyethoxy)aluminumhydride is comparable with lithium aluminum hydride (LAH, LiAlH₄).

It is a safer substitute for LAH and related hydrides. Sodium bis(2-methoxyethoxy)aluminumhydride exhibits similar reducing effects, but does not have the inconvenient pyrophoric nature, short shelf-life, or limited solubility of LAH. Upon contact with air and moisture, Sodium bis(2-methoxyethoxy)aluminumhydride reacts exothermically but does not ignite, and tolerates temperatures up to 200 °C. Under dry conditions it has unlimited shelf life. It is soluble in aromatic solvents, whereas LAH is only soluble in ethers. For example, a solution greater than 60 wt.% concentration in toluene is commercially available. The reagent can be modified to effect partial reductions.^[1]

References

1. Gugelchuk, M.; Silva, L. F. III; Vasconcelos, R. S.; Quintiliano, S. A. P. (2007). "Sodium Bis(2-methoxyethoxy)aluminum Hydride". Encyclopedia of Reagents for Organic Synthesis. New York: John Wiley & Sons. doi:10.1002/9780470842898.rs049.pub2.

External links

• "Red-Al, Sodium bis(2-methoxyethoxy)aluminumhydride". Organic Chemistry.