Hexamethyldisilazane

• Catalog No.: A15139
• CAS Number: 999-97-3
• M. F.: C6H19NSi2
• M. W.: 161.39276
• Purity: 98+%

SYNONYMS

• Title: 六甲基二硅杂氮烷
• IUPAC name: bis(trimethylsilyl)amine
• IUPAC Traditional name: hexamethyldisilizane
• Synonyms: Bis(trimethylsilyl)amine; HMDS

DATABASE IDS

• MDL Number: MFCD00008259
• CAS Number: 999-97-3
• EC Number: 213-668-5
• Merck Index: 144689
• Beilstein Number: 635752

PROPERTIES

• Purity: 98+%
• Boiling Point: 126°C
• Density: 0.774
• Flash Point: 8°C(46°F)
• Melting Point: -78°C
• Refractive Index: 1.4080
• GHS Hazard statements: H225-H311-H331-H302-H314-H318
• European Hazard Symbols: X
• European Hazard Symbols: Corrosive (C)
• European Hazard Symbols: Flammable (F)
• GHS Precautionary statements: P210-P303+P361+P353-P305+P351+P338-P361-P405-P501A
• Risk Statements: 11-20/21/22-34
• RTECS: JM9230000
• Safety Statements: 16-26-33-36/37/39-45-60
• Storage Warning: Moisture Sensitive
• TSCA Listed: 是
• Hazard Class: 3
• UN Number: UN2924
• Packing Group: II

REFERENCES

• Convenient, mild silylating reagent which generates gaseous ammonia as the only by-product (see Appendix 4). Non-acidic substrates normally require a catalyst.
• For conversion of carbonyl groups to silyl enol ethers, see Iodotrimethylsilane, A12902.
• Silylation of alcohols, including carbohydrates, is catalyzed by TMS chloride: J. Org. Chem., 23, 50 (1958); J. Am. Chem. Soc., 85, 2497 (1963); Chem. Ind. (London), 794 (1984). Silylation of phenols occurs readily, see also: Liebigs Ann. Chem., 20 (1973).
• HMDS in the presence of TMS chloride permits the selective O-silylation of amino alcohols: Synthesis, 990 (1988). Alcohols and phenols can be silylated in the presence of amines and thiols with ZnCl₂ as catalyst: Synth. Commun., 23, 1633 (1993).
• A range of catalysts for silylation with HMDS, including saccharin and sodium saccharin, has been recommended: J. Org. Chem., 47, 3966 (1982), for silylation of alcohols, phenols, thiols, carboxylic acids, amides, thioamides, hydroxamic acids, hydrazides, NH-groups of heterocycles, hydrazines, 1,3-diketones, etc. The use of TBAF (0.02 eq.) or iodine (0.01 eq.) also provide mild procedures for O-silylation: Tetrahedron Lett., 35, 8409 (1994); J. Org. Chem., 65, 7228 (2000).
• Can also function as a protected form of ammonia, e.g. to convert acid chlorides to primary amides: Synthesis, 517 (1985), and substituted maleic anhydrides to maleimides: Tetrahedron Lett., 31, 5201 (1990).
• In combination with DMSO, thiols are oxidized to disulfides under nearly neutral conditions: Synlett, 346 (2002).
• The Na, Li and K derivatives are useful strong bases; see Sodium bis(trimethylsilyl)amide, L13352, Lithium bis(trimethylsilyl)amide, L15012, and Potassium bis(trimethylsilyl)amide, L15022.