ChemicalBook CAS DataBase List 2,3-Dimethylpentane

2,3-Dimethylpentane synthesis

11synthesis methods

Product Name:2,3-Dimethylpentane
CAS Number:565-59-3
Molecular formula:C7H16
Molecular Weight:100.2

67-56-1 Synthesis

67-56-1
726 suppliers
$7.29/5ml-f

107-83-5
215 suppliers
$10.00/1g

108-08-7
72 suppliers
$47.29/2g

591-76-4 Synthesis

591-76-4
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$85.00/5mL

565-59-3
82 suppliers
$44.20/5g

589-34-4 Synthesis

589-34-4
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$95.79/5g

75-28-5 Synthesis

75-28-5
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$40.00/1g

78-78-4 Synthesis

78-78-4
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$20.00/25ML

96-14-0 Synthesis

96-14-0
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$22.19/5ml

79-29-8 Synthesis

79-29-8
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$20.00/1g

464-06-2 Synthesis

464-06-2
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$23.50/1g

Yield:-

Reaction Conditions:

indium (III) iodide at 180; for 0.5 h;

Steps:

23
In order to demonstrate that InI₃ catalyzed alkane homologation can be used to homologate C₆ alkanes other than 2,3-dimethylbutane, a reaction was performed using 2-methylpentane as the starting alkane. The reaction was performed using 6.2 mmol of MeOH, 6.2 mmol of 2-methylpentane, 4.13 mmol of InI₃ and 0.367 mmol of adamantane. A similar procedure to that described above for 2,3-dimethylbutane was used and the reaction was heated at 180 ⁰C for 30 minutes. GC analysis indicated that at the end of the reaction 27.4 mg of 2,3-dimethylpentane was formed and 267 mg of 2-methylpentane were recovered. A breakdown of the product distribution is shown in Table 8.Table 8: Products from the homologation of 2-methylpentane with MeOH.Product Yield (mg)Iso-butane 23.5Iso-pentane 10.72,3-dimethylbutane 1.762-methylpentane 2673-methylpentane 73.02,4-dimethypentane 12.1Triptane 5.032-methylhexane 5.252,3-dimethylpentane 27.43-methylhexane 8.48Cs alkanes 17.3[0088] The reaction is presumed to initially result in the methylation of 2- methylpentane to 2,3-dimethylpentane. The mechanism is proposed to be analogous to that described above for 2,3-dimethylbutane; initial abstraction of a hydride from 2- methylpentane to form the tertiary 2-methylpentyl carbocation, deprotonation to give 2-methyl-2-pentene, methylation to give the most substituted carbocation, in this case the tertiary 2, 3-dimethylpentyl carbocation, which subsequently picks up a hydride to form 2,3-dimethylpentane. Under the reaction conditions, 2,3- dimethylpentane is unstable and undergoes both isomerization and cracking reactions to form some of the other products observed. Isomerization of 2,3- dimethylpentane results in other C₇ alkanes, while products such as iso-butane and iso-pentane form from cracking (these cracking products are also probably formed from the C₆ and C₈ alkanes present). The reaction is not as selective as the methylation of 2,3-dimethylbutane to triptane because both 2-methylpentane and 2,3-dimethylpentane are more likely to undergo isomehzation reactions than 2,3- dimethylbutane or triptane. This is because 2-methylpentane and 2,3- dimethylpentane can undergo isomerization without a change in the length of main carbon backbone. Despite these isomerization side reactions, 2,3-dimethylpentane comprises approximately 50% of the C₇ fraction and highly branched C₇ alkanes (2,3- dimethylpentane, 2,4-dimethylpentane and triptane) comprise approximately 75% of the C₇ fraction. Furthermore, the presence of C₈ alkanes (determined using mass spectrometry) indicates that further methylation of C₇ species has occurred. Given the mechanism of methylation, it is believed that these species are also highly branched and will be more significantly more branched than 2-methylpentane. Thus, overall this is a process which increases the branching (often correlated with increased octane number) of the alkanes present. Attempts to homologate hexane with MeOH resulted in only small quantities of C₇ products and extremely long reaction times were required.