999-78-0

Basic information

• Product Name: 4,4-Dimethyl-2-pentyne
• Synonyms: 4,4-DIMETHYL-2-PENTYNE;T-BUTYLMETHYLACETYLENE;TIMTEC-BB SBB008719;(tert-C4H9)CequivCCH3;1-tert-butyl-1-propyne;2,2-dimethyl-3-pentyne;2-pentyne,4,4-dimethyl-;4,4-dimethyl-pent-2-yne
• CAS NO: 999-78-0
• Molecular Formula: C₇H₁₂
• Molecular Weight: 96.17
• EINECS: -0
• Product Categories: organic compound
• Mol File: 999-78-0.mol

Chemical Properties

• Melting Point: -82.4°C
• Boiling Point: 83°C
• Flash Point: -10°C
• Appearance: colorless/liquid
• Density: 0.718
• Vapor Pressure: 85.6mmHg at 25°C
• Refractive Index: 1.4071
• Water Solubility: Immiscible with water.
• BRN: 1733540
• CAS DataBase Reference: 4,4-Dimethyl-2-pentyne(CAS DataBase Reference)
• NIST Chemistry Reference: 4,4-Dimethyl-2-pentyne(999-78-0)
• EPA Substance Registry System: 4,4-Dimethyl-2-pentyne(999-78-0)

Safety Data

• Statements: 11
• Safety Statements: 9-16-33
• RIDADR: 3295
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 999-78-0(Hazardous Substances Data)

Usage

Uses

Used in Organometallic Chemistry:
4,4-Dimethyl-2-pentyne is used as a reagent in organometallic reactions for the regioselective insertion into the Pd-C bond of cyclopalladated complexes. This application is valuable for the synthesis of complex organic molecules and the development of new catalysts and materials.
Used in Pharmaceutical Synthesis:
In the pharmaceutical industry, 4,4-Dimethyl-2-pentyne is used as an intermediate in the preparation of pyrimidine-dione, an important class of compounds with potential biological activity. The reaction involves the coupling of 4,4-Dimethyl-2-pentyne with isocyanate in the presence of nickel/N-heterocyclic carbene, which facilitates the formation of the desired product.
These applications highlight the importance of 4,4-Dimethyl-2-pentyne in the fields of organometallic chemistry and pharmaceutical synthesis, where its unique properties and reactivity contribute to the development of new compounds and materials.

Synthesis Reference(s)

Tetrahedron Letters, 22, p. 2443, 1981 DOI: 10.1016/S0040-4039(01)92928-4

InChI:InChI=1/C7H12/c1-5-6-7(2,3)4/h1-4H3

Upstream product

• 74-88-4 methyl iodide 
• 145527-19-1 C₂₅H₂₇PS 
• 91229-76-4 W(CC(CH₃)3)(OC₆H₃(CH(CH₃)2)2)3 
• 75-05-8 acetonitrile 
• 999-79-1 4-chloro-4-methylpent-2-yne 
• 75-16-1 methylmagnesium bromide 
• 60-29-7 diethyl ether 

Downstream Products

• 70744-45-5 1,3,5-Tri-tert-butyl-2,4-dimethyl-benzene 
• 64235-56-9 (E)-2,4,4-trimethyl-1-phenyl-2-penten-1-one 
• 125540-61-6 (Z)-2-tert-Butyl-1-phenyl-but-2-en-1-one 
• 125540-75-2 (Z)-2,4,4-Trimethyl-1-phenyl-pent-2-en-1-one 
• 107-40-4 2,4,4-trimethylpent-2-ene 
• 75909-62-5 2-t-butyl-3-methyl-1,4-naphthoquinone 
• 32493-22-4 4-tert-butyl-5-methyl-6-phenylsulfanyl-[1,2,3]oxathiazine 2,2-dioxide 
• 15696-40-9 dodecacarbonyl triosmium 
• 669775-90-0 Os2(CO)6(μ-γ-C5H3O2)(μ-t-BuCHCMe) 
• 669775-87-5 Os3(CO)8(μ-CO)(μ-γ-C5H3O2)(t-BuCHCHCH2) 
• 117202-94-5 (2E)-2,4,4-trimethylpent-2-enal 
• 1453501-11-5 (Z)-3-(2,3,4,5-tetrafluorophenyl)-2-tert-butyl-but-2-enenitrile 
• 1453501-12-6 (Z)-2,4,4-trimethyl-3-(2,3,4,5-tetrafluorophenyl)pent-2-enenitrile 
• 139185-47-0 1,1-dichloro-4,4-dimethylpent-2-yne 

Relevant articles and documents

Properties and Reactivities of Zwitterionic Platinum(II)-ate Complexes Generated by Transforming Coordination of an Alkyne-Bisphosphine Ligand

Coordination of an alkyne-bisphosphine ligand with platinum(II) precursors produced a structural reorganization in the ligand backbone to form stable zwitterionic platinum(II) complexes bearing an anionic platinum center. The structural properties and reactivities of these complexes were investigated using X-ray crystallographic analyses, computational studies, and stoichiometric reactions involving oxidative addition and reductive elimination. These studies have shown that the enhanced nucleophilicity of the platinum center to alkyl halides promotes smooth oxidative addition and that the charge rebalance accelerates the dissociation of the halide anion from the platinum(IV) intermediate, which is essential in the carbon-carbon bond-forming step.

Kinetics and mechanism of gas-phase pyrolysis of ylides. Part 3. 1 Thermal reactivity of α-carbonyl- and thiocarbonyl-stabilized methylenetriphenylphosphoranes

Fourteen ketone/thione-stabilized triphenylphosphonium methylides were subjected to conventional gas-phase and flash vacuum pyrolysis (FVP). The kinetics of the first-order thermal gas-phase reactions of all these compounds were investigated over 360-653K temperature range. The values of the Arrhenius logA and energy of activation of these ylides averaged 11.52±0.34s -1 and 133.20±3.14kJmol-1, respectively. The products of sealed-tube (static) and FVP were analyzed and compared. A mechanism is proposed to account for the products of reaction. The rate constants [k (s-1)] of the substrates at 500K were calculated and used to substantiate the proposed mechanism of pyrolysis, and to rationalize the thermal gas-phase reactivities of the ylides under study.

Thermal rearrangement of thiocarbonyl-stabilised triphenylphosphonium ylides leading to (Z)-1-diphenylphosphino-2-phenylsulfenylalkenes

While thermolysis of thiocarbonyl-stabilised phosphonium ylides generally results in extrusion of Ph3PS to give alkynes, those with a PCH function instead undergo a novel P to S transfer of a phenyl group to give (Z)-configured 1-phosphino-2-su

Wittig-like reactions of tungsten alkylidyne complexes

W(C-t-Bu)(DIPP)3 (DIPP = 2,6-diisopropylphenoxide) reacts rapidly with acetonitrile to give [W(N)(DIPP)3]x and t-BuC≡CMe. It reacts with acetone, benzaldehyde, paraformaldehyde, ethyl formate, and N,N-dimethylformamide to give oxo vinyl complexes of the type W(O)(t-BuC=CR1R2)(DIPP)3. The tungstenacyclobutadiene complex W(C3Et3)(DIPP)3 reacts similarly with acetone, benzaldehyde, ethyl formate and N,N-dimethylformamide to give complexes of the type W(O)(EtC=CR1R2)(DIPP)3. The oxo vinyl complexes can be hydrolyzed by base to yield the expected olefinic product in good to excellent yield. The olefin product is mainly the cis isomer in most cases.