2-Methylpropane chlorination

A similar study of the chlorination of 2 methylpropane established that a tertiary hydrogen is removed 5 2 times faster than each primary hydrogen... 

Primary alkyl chlorides are fairly stable to fluorine displacement. When fluorinated, 1-chloropropane is converted to 1-chloroheptafluoropropane and 1-chloto-2-methylbutane produces 39% l-chlorononafluoro-2-methylbutane and 19% perfluoro-2-methylbutane. Secondary and tertiary alkyl chlorides can undergo 1,2-chlorine shifts to afford perfluonnated primary alkyl chlorides 2-Chloro-2-methylpropane gives l-chlorononafluoro-2-methylpropane, and three products are obtained by the fluorination of 3-chloropentane [7] (equation 1). Aerosol fluorina-tion of dichloromethane produces dichlorodifluoromethane which is isolated in 98% purity [4 (equation 2). If the molecule contains only carbon and halogens, the picture is different. Molecular beam analysis has shown that the reaction of fluorine with carbon tetrachlonde, lodotrichloromethane, or bromotrichloromethane proceeds first by abstraction of halogen to form a trichloromethyl radical [5]... 

As another example, 2-methylpropane yields 2-chloro-2-methylpropane and l-chloro-2-methylpropane in the ratio 35 65, along with more highly chlorinated products. 

A similar calculation for the chlorination of 2-methylpropane indicates that each of the nine primary hydrogens accounts for 65% + 9 = 7.2% of the product, while the single tertiary hydrogen (R3CH) accounts for 35% of the product. 

In contrast with alkane chlorination, alkane bromination is usually much more selective. In its reaction with 2-methylpropane, for example, bromine abstracts the tertiary hydrogen with greater than 99% selectivity, as opposed to the 35 65 mixture observed in the corresponding chlorination. 

In CC14 suspension, chlorine oxidation of [Ni(diamine)3]Cl2 affords unstable orange [Ni(diamine)3]Cl3 (diamine = en, 1,3-propanediamine, 1,2-cyclohexanediamine, 1,2-diamino-2-methylpropane, V-methylethanediamine) some of these species are stable for a few weeks in a... 

The product ratios for bromination of propane and 2-methylpropane are quite different from those seen above in the chlorination reaction, in that the more-favoured products by far are the secondary and tertiary halides respectively. Abstraction of a hydrogen atom by a bromine atom is now much more difficult than with a chlorine atom. The favoured product may be rationalized in terms of the relative strength of the C-H bond being broken, and the... 

Azetidin-2-one can be synthesized by treating 1-ethoxy-1-hydroxycy-clopropane with aqueous sodium azide at pH 5.5 (Scheme 8.7a). This type of construction has wider applications and A-substituted derivatives are formed from 1-amino-1-hydroxycyclopropanes in two steps first A-chlorination with tert- miy hypochlorite [2-methylpropan-2-yl chlo-rate(I)], and then treatment with silver ion in acetonitrile (ethanenitrile) to release chloride ion and trigger ring expansion of the tricycle (Scheme 8.7b). 

Only two alkanes have the molecular formula C4H10 butane and isobutane (2-methylpropane)— both of which give two monochlorides on free-radical chlorination. However, dehydrochlorination of one of the monochlorides derived from butane yields a mixture of alkenes. 

A complete FRET (Forster resonance energy transfer) system based on chlorophyll in the pores of FSM materials was accomplished by Kuroda s group.149,150 They first functionalized the FSM samples with 3-aminopropyl groups to guarantee an ideal position of the macroscopic chlorin units (in the pore center) and prevent their denaturation. Then they ligated chlorophyll derivatives that possess 3-(triethoxy-silyl)-A-methylpropan-l -amine groups to the pore walls. Zinc (for the FRET donor) and copper (for the FRET acceptor) were chosen as the central ions of the chlorins, which made it possible to initiate and record an efficient FRET process (Fig. 3.14). 

Explain why only one of the two chlorines of 1,2-dichloro-2-methylpropane is replaced by a hydroxy group when the compound is heated in water (see the preceding hydrolysis reaction). 

Another factor that limits the usefulness of the chlorination reaction in the laboratory is the lack of selectivity exhibited by the chlorine atom when more than one type of hydrogen is available to be abstracted. As an example, the reaction of isobutane with chlorine produces l-chloro-2-methylpropane and 2-chloro-2-methylpropane in a 2 1 ra-... 

Let s carefully analyze the reasons why these products are formed in this ratio. When a chlorine atom encounters an isobutane molecule, it may abstract a primary hydrogen, leading ultimately to the formation of l-chloro-2-methylpropane ... 

What are the defects in the following mechanism for the chlorination of 2-methylpropane by t-butyl hypochlorite You will need to consider the... 

As an additional exercise, can you work out how many isomers there are if any one of the hydrogens of 2-methylpropane is replaced with a chlorine atom Think before looking at the answer given in Figure 6.4.6. 

Free-radical chlorination of either w-propyl or isopropyl bromide gives 1-bromo-2-chloropropane, and of either isobutyl or / r/-butyl bromide gives l-bromo-2-chloro-2-methylpropane. What appears to be happening Is there any pattern to this behavior ... 

Methylcyclopropane shows strikingly different reactivity toward chlorine and bromine under radical chain conditions in CHjClj solution. The main product with chlorine is chloromethylcyclopropane (56%), along with smaller amounts of 1,3-dichlorobutane and l,3-dichloro-2-methylpropane. Bromine gives only... 

If 2-methylpropane is brominated at 125 °C in the presence of light, what percent of the product will be 2-bromo-2-methylpropane Compare your answer with the percent given in Problem 4 for chlorination. 

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