Hydrolysis of methyl chloride

Thermal chlorination of methane was first put on an industrial scale by Hoechst in Germany in 1923. At that time, high pressure methanol synthesis from hydrogen and carbon monoxide provided a new source of methanol for production of methyl chloride by reaction with hydrogen chloride. Prior to 1914 attempts were made to estabHsh an industrial process for methanol by hydrolysis of methyl chloride obtained by chlorinating methane. 

Combining the halogenation of methane with catalytic, preferentially gas-phase hydrolysis, methyl alcohol (and dimethyl ether) can be obtained in high selectivity (Scheme 18) . The hydrolysis of methyl chloride with caustic was first carried out by Berthelot in the mid 1800 . This first preparation of methyl alcohol, however,... 

Computational methods for treating organic reactions in solution have been reviewed in Japanese. Examples quoted include solvolysis, the Finkelstein reaction and the Menshutkin reaction. The same author carried out ab initio MO calculations at various levels on the hydrolysis of methyl chloride, in which up to 13 solvent water molecules were explicitly considered.It was found that the attacking H2O molecule kept two hydrogen atoms at the transition state, and the proton transfer from the attacking water to the water cluster began to occur after the transition state. Solute and solvent KIEs were calculated and compared with experimental results. The calculations for the system with 13 solvent water molecules reproduced the experimental energetics and deuterium KIEs fairly well. 

Table 4.23 Hydrolysis of methyl chloride over y-alumina-supported metal oxide/metal hydroxide catalysts (H2O/CHJCI ratio 10,648 K, GHSV 1200)...

Dichloroacetic acid is produced in the laboratory by the reaction of chloral hydrate [302-17-0] with sodium cyanide (31). It has been manufactured by the chlorination of acetic and chloroacetic acids (32), reduction of trichloroacetic acid (33), hydrolysis of pentachloroethane [76-01-7] (34), and hydrolysis of dichloroacetyl chloride. Due to similar boiling points, the separation of dichloroacetic acid from chloroacetic acid is not practical by conventional distillation. However, this separation has been accompHshed by the addition of a eotropeforming hydrocarbons such as bromoben2ene (35) or by distillation of the methyl or ethyl ester. 

Of the factors associated with the high reactivity of cyanuric chloride (high exother-micity, rapid hydrolysis in presence of water-containing solvents, acid catalysed reactions, liberation of up to 3 mol hydrogen chloride/mol of chloride, formation of methyl chloride gas with methanol, formation of carbon dioxide from bicarbonates), several were involved in many of the incidents recorded [1] (and given below). The acid catalysed self acceleration and high exothermicity are rated highest [2]. It is also a mildly endothermic compound (AH°f (s) +91.6 kJ/mol, 0.49 kJ/g). 

Methanol, a side product of methyl chloride hydrolysis, can be recovered and reused. In addition, recovered water is recycled. The products are formulated on site as solutions and are shipped in 1 to 30 gallon containers. 

The problems inherent in the hydrolysis of methylated polysaccharides are similar to those outlined, but, in addition, the possibility of occurrence of demethylation must be considered. This matter has been studied by Croon and coworkers,102 who found that hydrogen chloride, either in water or methanol, causes a significant amount of demethylation. Formolysis in 98% formic acid caused considerable degradation, whereas 90% formic acid or sulfuric acid gave acceptable results. The hydrolysis of a methylated dextran with 90% formic acid has been described in detail.103 The methanolysis of a methylated... 

When comparing the hydrolysis of methyl bromide with its reaction with Cl under the same conditions (i.e., [Cl-] = 100 mM, see Illustrative Example 13.2), we see that from a thermodynamic point of view, the hydrolysis reaction is heavily favored (compare ArG° values). This does not mean that the methyl bromide present is primarily transformed into methanol instead of methyl chloride (which it would be, if the reaction were to be thermodynamically controlled). In fact, in this and all other cases discussed in this chapter, we will assume that the reactions considered will be kinetically controlled that is, the relative importance of the various transformation pathways of a given compound will be determined by the relative reaction rates and not by the respective ArG° values. Thus, in our example, because CE is about a 103 times better nucleophile as compared to water (see Section 13.2) and because its concentration is about 103 times smaller than that of water (0.05 M versus 55.3 M), the two reactions would be of about equal importance under the conditions prevailing in this groundwater. Note that the product methyl chloride would subsequently also hydrolyze to yield methanol, though at a much slower rate. We will come back to this problem in Section 13.2 (Illustrative Example 13.2). 

Benzyl Alcohol Phenylmethanol or Hydroxytol-uene (called l -Oxy-T-methyl-benzol and benzyl chloride with Na or K carbonate in soln or by other methods. There are two commercial products technical grade and "FFC (free from chlorine) grade(Ref 3). Toxicity and fire hazard are discussed in Ref 5. It is used extensively in many branches of the chem industries, such as, for the manuf of esters(acetic, benzoic, sebacic, etc), as a solvent for cellulose esters ethers, etc. During WW I, it was used in a "dope for airplane fabrics... 

Fig. 27 Map of the transition states. The transition states are located as follows A, hydrolysis of methyl halides B, isopropyl transition states C, hydrolysis of t butyl chloride (or at D in Fig. 3) M, Menschutkin reactions...

Here we further examine the suitability of QM-SCRF methods in two chemical reactions the base-catalysed hydrolysis of methyl acetate in water, and the steric retardation of Sn2 reactions of chloride with ethyl and neopentyl chlorides in water. In the two cases the influence of the solvent is examined by using the MST version of the PCM model (see ref. [85] for a detailed description). 

Dimethyl-J>arabinose (XXXVI) has been isolated from the products of hydrolysis of methylated araban94 and of methylated damson gum.97 It has been synthesized49 from methyl 5-trityl-L-arabofurano-sides (afi mixture) (XXXV) by methylation with methyl iodide and silver oxide followed by removal of the trityl group by means of hydrogen chloride in chloroform and hydrolysis of the methyl glycosides. ... 

The dependence of volumes of activation, AV, on solvent composition for the hydrolysis of benzyl chloride in aqueous mixtures (Golinkin et al., 1966 Hyne et al., 1966) has been analysed using the solvent dependence of the partial molar volume of the initial state (Golinkin et al., 1967). In aqueous alcohols, as x2 increases, AV decreases to a minimum value at a mole fraction characteristic of the alcohol, e.g. x2 =0-1 for t-butyl alcohol, the intensity of the extremum increasing on going from methyl alcohol to t-butyl alcohol. The dependence of AV on x2 is a consequence of quite marked changes in the quantities 5m Vf and 8m V (Dickson and Hyne, 1971). For example, in ethyl alcohol + water mixtures, 5m V for benzyl chloride in the initial state has a maximum near x2 = 0-3, whereas 5m V has a shallow minimum near x2 = 0-1 (cf. V2 for Me4N+Cl- in these mixtures Lee and Hyne,... 

The rate constant for the hydrolysis of t-butyl chloride at 298 K decreases as x2 increases in DMSO + water mixtures (Heinonen and Tommila, 1965). A clear-cut contrast between TA and TNAN mixtures is shown by the volumes of activation and related parameters for the solvolysis of benzyl chloride in acetone + water (TA) and DMSO + water mixtures (Fig. 57). Thus, in the latter system, the curves show no marked extrema but there is a shallow minimum in AV near x2 = 0 4. Extrema in Sm AH and T. 5m AS for the hydrolysis of benzyl chloride are also smoothed out when the co-solvent is changed from acetone to DMSO (Tommila, 1966). A similar trend is observed in the kinetic parameters for the hydrolysis of chloromethyl and methyl trifluoroacetates (Cleve, 1972a). For example, in the case of the chloro derivative, 6mACp decreases gradually over the range 0 < x2 < 0-2 for DMSO + water mixtures, whereas a minimum is observed in this range for acetone + water mixtures. 

The hydrolysis must be carried out under a hood. The top of the reflux condenser should be connected with the ventilation pipe by means of a piece of glass tubing. The methyl alcohol contained in the reaction mixture escapes in the form of methyl chloride, along with some hydrogen chloride. 

Several different methods are used for the hydrolysis of methylated polysaccharides. As these ethers are generally insoluble in hot water (and, sometimes, even in cold water), it is usually necessary to use a non-aqueous or only partially aqueous medium for the initial hydrolysis. Treatment with methanohc hydrogen chloride (methanolysis) and subsequent hydrolysis of the methyl glycosides formed is widely employed. Another method involves heating with concentrated or aqueous formic acid (formo-... 

Hydrolysis of vinyl chlorides. One step in the Wichterle annelation with l,3-dichloro-cw-2-butene (1,214-215 2, 111-112) involves hydrolysis of an intermediate vinyl chloride to a ketone. This reaction has been conducted with cone. H2SO4. A new method involves reaction with mercury(II) trifluoroacetate, which can result in either a methyl or an ethyl ketone depending on the solvent. For example, hydrolysis of 1 with the mercury salt in CH3NO2, CH2CI2, or HOAc gives only the 1,5-diketone 2 in 90-97% yield hydrolysis in CH3OH gives 3 as the major product in 83% yield. ... 

Catalysis of the synthesis of benzoic anhydride and the hydrolysis of benzoyl chloride, diphenyl phosphorochloridate (DPPC), and benzoic isobutyric anhydride in dichloromethane-water suspensions by water-insoluble silanes and siloxanes, 3- and 4-trimethylsilylpyridine 1-oxide (3b and 3c, respectively), 1,3-bis(l-oxypyridin-3-yl)-l,1,3,3-tetramethyldisiloxane (4), and poly[methyl(l-oxypyridin-3-yl)-siloxane] (5) was compared with catalysis in the same systems by water-soluble pyridine 1-oxide (3a) and poly(4-vinylpyridine 1-oxide) (6). All catalysts were effective for anhydride synthesis and promoted the disproportionation of benzoic isobutyric anhydride. Hydrolysis of benzoyl chloride gave benzoic anhydride in high yield ( 80%) for all catalysts except 3a, which gave mixtures of anhydride (52%) and benzoic acid (39%). The order of catalytic activity for DPPC hydrolysis was 5 > 4 > 3b > 3a > 3c > 6. The results suggest that hydrophobic binding between catalyst and lipophilic substrate plays an important role in these processes. 

Horvath has reported conditions under which Pt11 is used to catalyze the conversion of methane to methyl chloride. The reaction conditions employed are indicated below, and avoid the hydrolysis of the methyl chloride to methanol. While the total quantity of methyl chloride formed is less than the amount of platinum initially present, the system is catalytic in Pt11 (Eq. 14), with PtIV serving as a stoichiometric oxidant and Cl2 stabilizing the system against precipitation of Pt° [61]. 

Complex kinetics, such as polymerization kinetics [19, 22], lead to complex types of behavior, even under isothermal operation, i.e., without the nonlinearity introduced by the rate constant s exponential dependence on temperature. Bailey [4] summarizes some cases of experimentally observed oscillations in CSTRs including chlorination of methyl chloride [7], hydrolysis of acetyl chloride [3], the reaction between methanol and hydrogen chloride [12], and the reaction between sodium thiosulfate and hydrogen peroxide [8],... 

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