Hexamethyldisilazane

Base Information

• Chemical Name: Hexamethyldisilazane
• CAS No.: 4039-32-1
• Deprecated CAS: 103737-28-6,127290-38-4,18186-75-9,761458-30-4,116638-29-0,116638-29-0,18186-75-9,761458-30-4
• Molecular Formula: C6H18LiNSi2
• Molecular Weight: 167.328
• Hs Code.: 29319090
• European Community (EC) Number: 213-668-5
• NSC Number: 252161,93895
• UN Number: 2924,2920
• UNII: H36C68P1BH
• DSSTox Substance ID: DTXSID2025395
• Nikkaji Number: J7.217F
• Wikipedia: Bis(trimethylsilyl)amine
• Wikidata: Q425001
• ChEMBL ID: CHEMBL3183662
• Mol file: 4039-32-1.mol

Synonyms:hexamethyldisilazane;hexamethylsilazane;hexamethylsilazane, aluminum salt;hexamethylsilazane, beryllium salt;hexamethylsilazane, cadmium salt;hexamethylsilazane, cerium (+3) salt;hexamethylsilazane, chromium (3+) salt;hexamethylsilazane, cobalt (2+) salt;hexamethylsilazane, europium (3+) salt;hexamethylsilazane, gadolinium (3+) salt;hexamethylsilazane, gallium salt;hexamethylsilazane, germanium (2+) salt;hexamethylsilazane, holmium (3+) salt;hexamethylsilazane, indium (3+) salt;hexamethylsilazane, iron (3+) salt;hexamethylsilazane, lanthanum (3+) salt;hexamethylsilazane, lead (2+) salt;hexamethylsilazane, lithium salt;hexamethylsilazane, lutetium (3+) salt;hexamethylsilazane, magnesium salt;hexamethylsilazane, manganese (2+) salt;hexamethylsilazane, mercury (2+) salt;hexamethylsilazane, neodymium (3+) salt;hexamethylsilazane, potassium salt;hexamethylsilazane, praseodymium (3+) salt;hexamethylsilazane, samarium (3+) salt;hexamethylsilazane, scandium (3+) salt;hexamethylsilazane, silanamine-(15)N-labeled;hexamethylsilazane, sodium salt;hexamethylsilazane, thallium (3+) salt;hexamethylsilazane, tin (2+) salt;hexamethylsilazane, titanium (3+) salt;hexamethylsilazane, uranium (3+) (3:1) salt;hexamethylsilazane, vanadium (3+) salt;hexamethylsilazane, ytterbium (3+) salt;hexamethylsilazane, yttrium (3+) salt;hexamethylsilazane, zinc salt;N-lithiohexamethyldisilazane;sodium hexamethyldisilazide

Chemical Property of Hexamethyldisilazane

Chemical Property:

• Appearance/Colour: light yellow to yellow crystalline powder
• Melting Point: 73 °C
• Refractive Index: n20/D 1.425(lit.)
• Boiling Point: 126 °C at 760 mmHg
• Flash Point: 30 °C
• PSA: 3.24000
• Density: 0.891 g/mL at 25 °C
• LogP: 2.42250
• Storage Temp.: below 5° C
• Sensitive.: Air & Moisture Sensitive
• Solubility.: hydrolysis
• Water Solubility.: hydrolysis
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 1
• Rotatable Bond Count: 2
• Exact Mass: 161.10560268
• Heavy Atom Count: 9
• Complexity: 76.2
• Transport DOT Label: Flammable Liquid Corrosive

Purity/Quality:

99% ^*data from raw suppliers

Lithium hexamethyldisilazane ^*data from reagent suppliers

Safty Information:

• Pictogram(s): F, C, N
• Hazard Codes: F,C,N
• Statements: 11-34-48/20-63-65-67-51/53-35-20-62-14-40-37-19
• Safety Statements: 9-16-26-29-33-36/37/39-45-61-62-57-43

MSDS Files:

SDS file from LookChem

Useful:

• Chemical Classes: Metals -> Metalloid Compounds (Silicon)
• Canonical SMILES: C[Si](C)(C)N[Si](C)(C)C
• Physical properties: distillable low-melting solid; mp 70–72 °C, bp 115 °C/1mmHg. LHMDS is a cyclic trimer in the solid state,3 whereas in benzene solution it exists in a monomer–dimer equilibrium. LHMDS exists as a tetramer-dimer mixture in hydrocarbons and as a dimer-monomer mixture in THF and ether. Treatment of LHMDS with trialkylamines increases the monomer concentration, whereas the use of diamines affords exclusively the corresponding chelated monomer. LHMDS is less soluble, less basic, more stable, and much less sensitive to air compared to lithium diisopropylamide. pKa 29.5 (THF, 27 °C).
• Uses: Lithium bis(trimethylsilyl)amide is used as nonnucleophilic base to generate kinetic ketone and ester enolates. It is considerably more selective than LDA and undesired reductions (e.g., of nonenolizable ketones observed in the case of LDA) can be avoided by using LHMDS. Lithium Hexamethyldisilazide is widely used as strong nonnucleophilic base Lithium bis(trimethylsilyl)amide is a base used in preparation of dienes and enolates. It is used to catalyze the addition of phosphine P-H bonds to carbodiimides leading to phosphaguanidines. Lithium bis(trimethylsilyl)amide is also used in a novel three-step synthesis of disubstituted 1,2,5-thiadiazoles.

Technology Process of Hexamethyldisilazane

There total 33 articles about Hexamethyldisilazane which guide to synthetic route it. The literature collected by LookChem mainly comes from the sharing of users and the free literature resources found by Internet computing technology. We keep the original model of the professional version of literature to make it easier and faster for users to retrieve and use. At the same time, we analyze and calculate the most feasible synthesis route with the highest yield for your reference as below:

synthetic route:

Reference yield: 99.5%

1,1,1,3,3,3-hexamethyl-disilazane (999-97-3) → lithium hexamethyldisilazane (4039-32-1)

Guidance literature:

With n-butyllithium; In hexane; at 20 ℃; Inert atmosphere;

DOI:10.1002/ejic.202000434

Reference yield:

C10H8LiN (97254-19-8) + 1,1,1,3,3,3-hexamethyl-disilazane (999-97-3) → C6H4NCH2CHCCH2 (491-35-0) + lithium hexamethyldisilazane (4039-32-1)

Guidance literature:

In tetrahydrofuran; diethyl ether; at 27 ℃; Equilibrium constant;

DOI:10.1021/jo00217a050

Reference yield:

2,3-benzofluorene lithium salt + 1,1,1,3,3,3-hexamethyl-disilazane (999-97-3) → 2,3-benzofluorene (243-17-4) + lithium hexamethyldisilazane (4039-32-1)

Guidance literature:

In tetrahydrofuran; Concentration; Equilibrium constant;

DOI:10.1021/jo202253q

upstream raw materials:

lithium bis(trimethylsilyl)amide diethyl etherate

N,N,N'-tris(trimethylsilyl)phosphenimidous amide

2,2,6,6-tetramethylpiperidinyl-lithium

tetrakis(trimethylsilyl)tetrazene

Downstream raw materials:

tris(trimethylsilyl)amine

bis(trimethylsilyl)carbodi-imide

N-phenyl-N'-(trimethylsilyl)carbodiimide

(2S,4S,5R)-2-(1,1,1,3,3,3-Hexamethyl-disilazan-2-yl)-3,4-dimethyl-5-phenyl-[1,3,2]oxazaphospholidine

Refernces

• 1、 Kim, Yeong-Joon,Streitwieser, Andrew. "Equilibrium constants and alkylation kinetics of two lithium enolates/LiHMDS mixed aggregates in THF". . p. 573 - 575. Retrieved 2002.
• 2、 Crocco, Guy L.,Gladysz, J. A.. "Divergent Kinetic and Theromodynamic Acidity in Organotransition-Metal Hydride Complexes: Synthesis, Structure, and Reactivity of the Rhenium Anion of Li+5-C5H5)Re(NO)(PPh3)>-". . p. 6110 - 6118. Retrieved 1988.
• 3、 Lappert, Michael F.,Slade, Martin J.,Singh, Anirudh,Atwood, Jerry L.,Rogers, Robin D.,Shakir, Riz. "Structure and Reactivity of Sterically Hindered Lithium Amides and Their Diethyl Etherates: Crystal and Molecular Structures of (OEt)2>2 and 4". . p. 302 - 304. Retrieved 1983.
• 4、 Podraza, Kenneth F.,Bassfield, Ronald L.. "Evaluation of Lithium Amide Base Formation at Low Temperature via 13C NMR Spectroscopy". . p. 2643 - 2644. Retrieved 1988.
• 5、 Whitelaw, Michael T.,Kennedy, Alan R.,Mulvey. "Structural Similarity in a Series of Alkali Metal Aluminates with Heteroleptic tert-Butoxide–Isobutyl Ligand Sets". . p. 2912 - 2918. Retrieved 2020.
• 6、 Sarraje,Lorberth. "". . p. 113,118. Retrieved 1978.
• 7、 Ramírez-Meneses,Montiel-Palma,Domínguez-Crespo,Izaguirre-López,Palacios-Gonzalez,Dorantes-Rosales. "Shape-and size-controlled Ag nanoparticles stabilized by in situ generated secondary amines". . p. S51 - S61. Retrieved 2015.
• 8、 -. "Process for preparing lithium bis (trimethyldisilyl) amide". Paragraph 0020-0022. . Retrieved 2021/04/28.
• 9、 Ba?i?, Goran,Zanders, David,Mallick, Bert,Devi, Anjana,Barry, Seán T.. "Designing Stability into Thermally Reactive Plumbylenes". . p. 8218 - 8226. Retrieved 2018/07/25.