T-butyl chloride

Draw the mechanism of the imaginary reverse reaction, the formation of t-butyl chloride from the alcohol. 

Relative Rate of SnI Solvolysis of te/t-Butyl Chloride as a Function of Solvent Polarity ... 

A comparison of rate and product composition of tiie products from reaction of t-butyl chloride with NaOMe in methanol and methanol-DMSO mixtures containing NaOMe has been done. Interpret the effect of the change of solvent composition and NaOMe concentration. 

Is the electrophilic addition of hydrogen chloride to 2-methyl-propene the reverse of the El or the E2 elimination reaction of fe/t-butyl chloride ... 

This activation of the ortho position is most strikingly illustrated in the reactivity of 2,5-dimethylthiophene, which competitive experiments have shown to undergo the SnCb-catalyzed Friedel-Crafts reaction more rapidly than thiophene and even 2-methylthiophene. The influence of the reagent on the isomer distribution is evident from the fact that 2-methoxythiophene is formylated and bromi-nated (with A -bromosuccinimide) only in the 5-position. Similarly, although 3-bromo-2-methylthiophene has been detected in the bromi-nation of 2-methylthiophene with bromine, only the 5-isomer (besides some side-chain bromination) is obtained in the bromination of alkylthiophenes with A -bromosuccinimide. ° However, the mechanism of the latter type of bromination is not established. No lines attributable to 2-methyl-3-thiocyanothiophene or 2-methyl-3-chIoro-thiophene could be detected in the NMR spectra of the substitution products (5-isomers) obtained upon thiocyanation with thiocyanogen or chlorination with sulfuryl chloride. 2-Methyl- and 2-ethyl-thiophene give, somewhat unexpectedly, upon alkylation with t-butyl chloride in the presence of Feds, only 5-t-butyl monosubstituted and... 

The calculated isotope effects for the solvolyses of t-butyl chloride-dg (previously estimated by Bartell, 1961a) and acetyl chloride-ds were much weaker than the experimentally observed ones. The authors conclude (Karabatsos et al., 1967) that in ordinary systems where hyperconjugation (from the j8-position) is possible, the effect of non-bonded interactions accounts for only a small part (less than 10%) of the observed isotope effect. 

G.l.c. studies of tributylphosphine, dialkyl phosphites, and dialkyl alkylphosphonates are reported. Tributyl phosphate in nitric acid can be estimated by g.l.c. if a glass column is used. Tetraethyl pyrophosphate has been directly determined on a nanogram scale by g.l.c., whereas it was found most convenient to first convert the tetra-aryl pyrophosphates by methanolysis to diarylmethyl phosphates. Phosphorochloridates were converted by t-butyl alcohol into t-butyl chloride before analysis. G.l.c. studies of pesticides have been reported and the isomeric thiophosphates (138a) and (138b) have quite different retention times. ... 

By contrast, hydrolysis of the tertiary halide 2-chloro-2-methyl-propane (3,t-butyl chloride) in base is found kinetically to follow equation [2], i.e. as the rate is independent of [eOH], this can play no part in the rate-limiting step. This has been interpreted as indicating that the halide undergoes slow ionisation (in fact, completion of the R->-Cl polarisation that has already been shown to be present in such a molecule) as the rate-limiting step to yield the ion pair R Cle (4) followed by rapid, non rate-limiting attack by eOH or, if that is suitable, by solvent, the latter often predominating because of its very high concentration ... 

In 1948, Grunwald and Winstein2 4 attempted to define the ionizing power of a solvent by the Y parameter, based on the comparison of the rate for the solvolysis of t-butyl chloride. In 1956, Kosower5 made an attempt to define the polarity of a medium (solvent) by introducing the Z parameter based on the spectroscopic properties (in various solvents)... 

The Friedel-Crafts alkylation of 2,5-dimethylthiophene was also studied (57). In contradistinction to thiophene itself, it was reported that this substituted thiophene alkylated readily with only a minor amount of polymerization when an active halide such as t-butyl chloride was used. With less reactive halides, e.g. n-butyl chloride, some replacement of the methyl groups in 2,5-dimethylthiophene occurred and polymerization increased. 

Nakane ei al. (1964) established equilibrium constants of boron isotope exchange between boron trifluoride gas on one side and boron trifluoride methyl fluoride, methyl chloride, isopropyl chloride and t-butyl chloride. The value of the equilibrium constants, which represents the thermodynamic isotope effect, was related to the polarity, stability and catalytic activity of the complexes. 

Attempts to obtain alkylcarbonium complexes by dissolving alkyl chlorides (bromides) in liquid Lewis acid halides (stannic chloride, titanium (IV) chloride, antimony pentachloride, etc.) as solvent were unsuccessful. Although stable solutions could be obtained at low temperature with, for example, t-butyl chloride, the observed N.M.R. chemical shifts were generally not larger than 0 5 p.p.m. and thus could be attributed only to weak donor-acceptor complexes, but not to the carbonium ions. The negative result of these investigations seems to indicate that either the Lewis acids used were too weak to cause sufficient ionization of the C—Cl bond, or that the solvating effect of the halides... 

The relative rates of solvolysis of camphene hydrochloride and t-butyl chloride indicate that the free energy of activation is 5 kcal mole higher with the latter compound. This might be attributed either to non-classical stabilization of the camphenyl transition state... 

Solvolysis of t-butyl chloride in the presence of methylcyclopentane yields a t-butyl ion which is quantitatively converted to isobutane before exchanging hardly any protons with the acid. 

Begin by examining the conversion of t-butyl alcohol to t-butyl chloride. This process has a 96 percent yield. (This is a good thing ) The overall reaction is shown in Figure 2-9. 

Tertiary alkyl halides undergo a series of reactions when treated with hydrogen fluoride. f-Amyl chloride by means of reactions catalyzed by hydrogen fluoride yielded a series of teritary chlorides including f-butyl chloride (Simons et al., 35). t-Butyl chloride gives the same series of... 

It is assumed in the Hughes-lngold rules that the entropy of activation is small relative to the enthalpy of activation, that is, AG AH, and that the temperatnre effect on the rate follows with an assumed temperature independent valne of AH. If the nnmber of solvent molecules solvating the activated complex is very different from that solvating the reactants, then this assnmption is no longer valid. This is the case in the solvolysis of t-butyl chloride in water compared to, say, ethanol. 

Because of the orientational freedom, plastic crystals usually crystallize in cubic structures (Table 4.2). It is significant that cubic structures are adopted even when the molecular symmetry is incompatible with the cubic crystal symmetry. For example, t-butyl chloride in the plastic crystalline state has a fee structure even though the isolated molecule has a three-fold rotation axis which is incompatible with the cubic structure. Such apparent discrepancies between the lattice symmetry and molecular symmetry provide clear indications of the rotational disorder in the plastic crystalline state. It should, however, be remarked that molecular rotation in plastic crystals is rarely free rather it appears that there is more than one minimum potential energy configuration which allows the molecules to tumble rapidly from one orientation to another, the different orientations being random in the plastic crystal. 

In the absence of monomers, trimethylaluminum (0.5 mol) reacts with t-butyl chloride (1.0 mol) at -78°C to give a quantitative yield of neopentane [22], Kennedy [23] found that aluminum trialkyls (AlMe3, AlEt3, A1Bu3) in the presence of certain alkyl halides are efficient initiators for the cationic polymerization of isobutylene, styrene, etc. 

A successful procedure for the formation of 2,5-di-t-butylfuran involves reaction of the parent heterocycle with t-butyl chloride in the presence of iron(III) chloride and iron(III) oxide (82CI(L)603). 

In equation (10), Y is the ionizing power of the solvent and N its nucleophilic power with m and / measuring the sensitivity of the substrate to these factors. By selecting model compounds, e.g. t-butyl chloride, where only Y should be important and methyl chloride, where both N and Y would be important, then it is possible to obtain values of Y and N for various solvent mixtures. An examination of the variation of the rate of reaction of a given substrate in these solvents according to equation (10) would then reveal the relative importance of the associative and dissociative character to the reactions. 

FIGURE 4.6 The mechanism of formation of te/t-butyl chloride from te/t-butyl alcohol and hydrogen chloride. 

The first-order rate constant for ethanolysis of the allylic chloride 3-chloro-3-methyl-l-butene is over 100 times greater than that of fe/t-butyl chloride at the same temperature. 

Step 1 Once generated by the reaction of fe/T-butyl chloride and aluminum chloride, tot-butyl cation attacks the tt electrons of benzene, and a carbon-carbon bond is formed. 

Pivalonitrile (33.2 g) and t-butyl chloride (44.4 g) were added under nitrogen over 1 h to a well-stirred suspension of sodium sand (18.4 g) in a mixture of light petroleum (80 ml), THF (20 ml) and methanol (1ml), keeping the reaction temperature between 15 and 20°C during addition. The mixture was stirred for 3h. Chlorobenzene (2 g) in THF (5 ml) was added dropwise over 10 min, and stirring continued (1 h). Methanol (20 ml) was cautiously added over 0.5 h, followed by water, until clear phases separated. The aqueous phase was extracted with ether (3 X 50 ml). The combined organic phases were dried and concentrated under reduced pressure. Distillation afforded the pure imine (63%), b.p. 62-63°C/19 torr. 

Another estimate seemed to support an inductive contribution to deuterium IEs on the acidity of carboxylic acids.37 This IE on acidity of some carboxylic acids was attributed to an inductive effect arising from the electrostatic interaction of the C-H or C-D dipole with the negative charge of the carboxylate, as expressed in Equation (31). The derivative dpK/dfi was estimated from the effect of a C-Cl dipole on acidity, using the difference in pATas of trichloroacetic acid (0.63) and acetic acid (4.75) and the difference between the dipole moments of t-butyl chloride (2.13 D) and isobutane (-0.13 D). Next Afj, was estimated as 0.0086 D, the difference between the dipole moments of (CH3)3CD and (CH3)3CH. Thus ApK was estimated as 0.005 per D, in excellent agreement with the observed 0.014 for acetic-d3 acid. Moreover, the IE of 0.002 per D in pivalic-J9 acid is consistent with a 2.8-fold falloff factor for inductive effects. Yet those estimates depend crucially on the difference between the dipole moments of isobutane and isobutane-d, which is unusually large, amounting to 6.5% of either s total dipole moment. 

There are relatively few synthetic routes to 2,7-naphthyridines almost all are multistage and rely on annulation of a second pyridine ring to a suitably functionalised pyridine precursor. French workers have described an efficient, one-pot synthesis of l,3,6,8-tetramethyl-2,7-naphthyridine 1 which involves treatment of a mixture of acetyl chloride (1.6 mol) and aluminium chloride (0.3 mol) with t-butanol or t-butyl chloride (0.1 mol) at 35°C for half an hour, followed by careful addition of the reaction mixture to liquid ammonia. This gave 37% of 2,4,6-trimethylpyridine and 63% of the naphthyridine 1 in a total yield of 91%. 

The reaction is illustrated by the preparation of t-butyl chloride (Expt 5.49). 

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