Neophyl chloride, C₆H₅C(CH₃)₂CH₂Cl, is a halogenated

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with unusual nucleophilic substitution properties. Neophyl chloride is used to form a versatile

organolithium reagent In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom ...

, neophyl lithium, by reaction with lithium.

Preparation

Neophyl chloride was first synthesized by Haller and Ramart by reacting the chlorinating reagent

thionyl chloride Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately per year bein ...

with neophyl alcohol: :C₆H₅C(CH₃)₂CH₂OH + SOCl₂ → C₆H₅C(CH₃)₂CH₂Cl + HCl + SO₂ It is easily prepared on a large scale by combining

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms ...

and

methallyl chloride Methallyl chloride is the organic compound with the formula CH2=C(CH3)CH2Cl. It is a colorless liquid and a lacrymator. Its properties are similar to those of allyl chloride. It is a strong alkylating agent used to install isobutenyl groups. ...

in the presence of a

catalytic Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

quantity of sulfuric acid. The reaction is an example of an

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic n ...

. :H₂C=C(CH₃)CH₂Cl + C₆H₆ → C₆H₅C(CH₃)₂CH₂Cl Alternatively ''tert''-butylbenzene can be

chlorinated In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polyme ...

with

sulfuryl chloride Sulfuryl chloride is an inorganic compound with the formula SO2Cl2. At room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature, as can be inferred from its rapid hydrolysis. Sulfuryl chloride is ...

Reactions and applications

Neophyl chloride can be used to form an organolithium reagent, neophyl lithium, by reaction with

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

. Organolithium reagents are useful due to their

nucleophilic In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...

properties and their ability to form carbon-to-carbon bonds, like in reactions with

carbonyl In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containi ...

s. :C₆H₅C(CH₃)₂CH₂Cl + 2Li → C₆H₅C(CH₃)₂CH₂Li + LiCl Neophyl chloride is of interest to organic chemists due to its substitution properties. Neophyl chloride is a

neopentyl Pentyl is a five-carbon alkyl group or substituent with chemical formula -C5H11. It is the substituent form of the alkane pentane. In older literature, the common non-systematic name amyl was often used for the pentyl group. Conversely, the name ...

halide which means it is subject to the neopentyl effect. This effect makes SN₂

nucleophilic substitution In chemistry, a nucleophilic substitution is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile). The ...

highly unlikely because of steric interactions due to the branching of the β-carbon. No

rotamer In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted just by rotations about formally single bonds (refer to figure on single bond rotation). While any two arrangements of atoms in a mole ...

of the molecule would allow a backside attack of the α carbon. β-Hydride elimination also does not occur with neophyl derivatives as this group lacks hydrogens at the β positions. These factors make neophyl chloride a precursor to intermediates that resist common substitution and

elimination reaction An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one- or two-step mechanism. The one-step mechanism is known as the E2 reaction, and the two-step mechanism is known as the E1 r ...

References

{{Reflist Organochlorides Phenyl compounds