2-Phenylpentane

• CAS: 2719-52-0
• Catalog Number: ACM2719520
• Category: Main Products
• Molecular Weight: 148.24
• Molecular Formula: C₁₁H₁₆
• Synonyms: SEC-PENTYLBENZENE;SEC-AMYLBENZENE;(1-METHYLBUTYL)BENZENE;2-PHENYLPENTANE;(1-Methybutyl)benzene;1-Methyl-1-Phenylbutane;1-Methyl-n-butylbenzene;1-Phenyl-1-methylbutane
• IUPAC Name: pentan-2-ylbenzene
• InChI Key: LTHAIAJHDPJXLG-UHFFFAOYSA-N
• Boiling Point: 192ºC at 760mmHg
• Flash Point: 60.6ºC
• Density: 0.86
• Appearance: Colourless liquid
• EC Number: 220-324-8
• Exact Mass: 148.12500
• H-Bond Acceptor: 0
• H-Bond Donor: 0
• Safety Description: 24/25

Case Study

Acid-Catalyzed Dealkylation of 2-Phenylpentane and Formation of Branched Alkanes

Roberts, Royston M., et al. Journal of Organic Chemistry 43.15 (1978): 2977-2982

This study investigated the acid-catalyzed dealkylation of 2-phenylpentane and the distribution of alkane products, using aluminum chloride (AlCl₃) as the main catalyst and comparing with other acid catalysts such as Al₂Br₆ and HF-SbF₅. 2-Phenylpentane was synthesized by adding pentylmagnesium bromide to acetophenone, followed by dehydration of the resulting carbinol and catalytic hydrogenation. Dealkylation reactions were carried out at temperatures ranging from 30°C to 100°C with a mole ratio of 2-phenylpentane/AlCl₃/H₂O = 1.0:0.33:0.11, and the gaseous and liquid products were analyzed by gas chromatography (GLC) and mass spectrometry. Results showed that 2-phenylpentane underwent dealkylation to produce alkanes, with isopentane as the major product (96% at 100°C) and only trace amounts of n-pentane. At 30°C, dealkylation efficiency was low (1% mol conversion) but yielded 100% isopentane. Adding a hydride donor (methylcyclohexane) increased the proportion of n-pentane to 16% at 80°C, while diluting with benzene reduced n-pentane formation. Liquid products included alkylbenzene isomers such as 2-methyl-1-phenylbutane and 3-phenylpentane, as well as cyclialkylation byproducts. These studies demonstrate that 2-phenylpentane undergoes acid-catalyzed dealkylation primarily to form branched alkanes via secondary carbocation rearrangement, with hydride donation influencing the ratio of normal to branched isomers.
The in vitro dealkylation of 2-phenylpentane was verified through controlled experiments and product analysis. In typical reactions, 2-phenylpentane (0.10 mol) was added to activated AlCl₃ and heated in an oil bath, with gaseous products collected and analyzed by GLC using a 20 ft 10% SE-30 column. Liquid reaction mixtures were quenched with ice-water-acetone, extracted with ether, and purified before GLC analysis with cyclohexane as an internal standard. For reactions with Al₂Br₆ or HF-SbF₅, volatile products were trapped under nitrogen flow, and organic layers were washed, dried, and analyzed. The effect of hydride donors and solvents was investigated by adding methylcyclohexane or benzene to the reaction system. Reaction temperatures and durations were varied to assess their impact on dealkylation efficiency and product distribution, with data analyzed by comparing retention times with authentic alkane standards.

Study on the Aluminum Chloride-Catalyzed Alkylation and Rearrangement of 2-Phenylpentane

Roberts, Royston M., et al. Journal of Organic Chemistry 41.4 (1976): 659-664

This study investigated the alkylation and rearrangement behavior of 2-phenylpentane in aluminum chloride (AlCl₃)-catalyzed reactions with arenes (benzene and p-xylene), focusing on product distribution and competing reaction pathways. 2-phenylpentane was synthesized by hydrogenating the carbinol derived from acetophenone and pentylmagnesium bromide, and its purity was confirmed by GLC, IR, and NMR. Alkylation reactions were conducted using two methods: Method A (AlCl₃ added to arene + 2-phenylpentane precursor) and Method B (AlCl₃ added to precursor first, then arene), at temperatures ranging from -20°C to 25°C. Results showed that at 25°C, alkylation of benzene with 2-chloropentane (precursor to 2-phenylpentane) yielded a 74:26 ratio of 2-phenylpentane to 3-phenylpentane. At -20°C, no product rearrangement occurred, and Method A produced a 72:28 ratio, while Method B (after precursor isomerization) gave a 66:34 ratio. For p-xylene alkylation at -20°C, 2-phenylpentane formed a stable 67:33 ratio of 2-p-xylylpentane to 3-p-xylylpentane, whereas 3-chloropentane (precursor) initially gave a 48:52 ratio that shifted to 64:36 over 2 hours. These studies demonstrate that 2-phenylpentane undergoes isomerization to 3-phenylpentane under AlCl₃ catalysis, with reaction temperature, mixing order, and arene substrate influencing product distribution.
The in vitro alkylation and rearrangement of 2-phenylpentane were verified through controlled experiments and product analysis. Reactions were performed with a mole ratio of arene:precursor:AlCl₃ = 4:1:0.1, with hexane added to prevent freezing at low temperatures. Aliquots were withdrawn at intervals, quenched in water, and analyzed by GLC using Bentone-34/silicone columns to separate isomeric products. Rearrangement tests confirmed no isomerization of 2-p-xylylpentane at -20°C, while 5-22% rearrangement occurred at 0°C. Kinetic analysis revealed that 2-chloropentane alkylates arenes 2-3 times faster than 3-chloropentane, and AlCl₃·CH₃NO₂ catalyst suppressed product rearrangement at 25°C. Product identities were confirmed by comparing retention times with authentic standards and complementary IR/NMR analyses.

Custom Q&A

What is the molecular formula of 2-Phenylpentane?

The molecular formula of 2-Phenylpentane is C11H16.

What are the synonyms of 2-Phenylpentane?

The synonyms of 2-Phenylpentane are sec-Pentylbenzene and pentan-2-ylbenzene.

What is the molecular weight of 2-Phenylpentane?

The molecular weight of 2-Phenylpentane is 148.24 g/mol.

When was 2-Phenylpentane created?

2-Phenylpentane was created on March 27, 2005.

When was 2-Phenylpentane last modified?

2-Phenylpentane was last modified on October 21, 2023.

What is the IUPAC name of 2-Phenylpentane?

The IUPAC name of 2-Phenylpentane is pentan-2-ylbenzene.

What is the InChI of 2-Phenylpentane?

The InChI of 2-Phenylpentane is InChI=1S/C11H16/c1-3-7-10(2)11-8-5-4-6-9-11/h4-6,8-10H,3,7H2,1-2H3.

What is the InChIKey of 2-Phenylpentane?

The InChIKey of 2-Phenylpentane is LTHAIAJHDPJXLG-UHFFFAOYSA-N.

What is the canonical SMILES of 2-Phenylpentane?

The canonical SMILES of 2-Phenylpentane is CCCC(C)C1=CC=CC=C1.

What is the CAS number of 2-Phenylpentane?

The CAS number of 2-Phenylpentane is 2719-52-0.