Acetic chloro

The relative rates of hydrolysis of acetate, chloro-, dichloro-, and trichloroacetates have been compared and give the following relative rates 1 760 1.6 x 10 10. ... 

Mobile phase composition 1 = toluene-ethyl acetate-formic acid (30 10 10, v/v) 2 = toluene-ethyl acetate-formic acid (55 20 25, v/v) 3 = toluene-acetone-formic acid (7 6 1, v/v) 4 = benzene-ethyl acetate-formic acid (30 15 5, v/v) 5 = chloroform-methanol-formic acid (15 3 2, v/v) 6 = chloro-form-methanol-formic acid (147 30 23, v/v) 7 = Toluene-chloroform-acetone-formic acid (8 4 3 3, v/v) 8 = chloroform-methanol-formic acid (37 8 5, v/v) 9 = chloroform-methanol-formic acid (36 9 5, v/v) 10 = ethyl acetate-chloroform-formic acid (24 21 5, v/v) 11 = ethyl acetate-chloro-form-formic acid (23 21 6, v/v). 

The same information can be obtained by carrying out a range of solventpartitioning experiments, typically between water and ethyl acetate, chloro-form/dichloromethane, or hexane, followed by assay to determine how the compound distributes itself (Note 2). 

This compound is similar in type to the sodium acet-bromoamide, CHjCONNaBr, which is an intermediate compound in Hofmann s amine synthesis (p. 127). If a weak acid (such as acetic acid) is now added to the solution of the chloro-sodio-amide, the latter compound reacts with the hypo-chlorous acid giving the sulphon-dichloro amide, which being insoluble in water, rapidly separates ... 

Dissolve 10 g. of chloro- 2,4-dinitrobenzenet in 50 ml. of dioxan in a 250 ml. conical flask. Dilute 8 ml. of hydrazine hydrate with an equal volume of water and add this slowly with shaking to the dioxan solution, keeping the temperature between zo " and 25°. Heat under reflux for 10 minutes to complete the reaction and then add 5 ml. of ethanol and heat again for 5 minutes. Cool and filter oflF the orange 2,4-dinitrophenylhydra-zine. Recrystallise the dry product from ethyl acetate m.p. 200° (decomp.). Yield, 7 g. 

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g. 

Unsymmetrical diaryls may be prepared by treating an aryl diazonium salt solution with sodium hydroxide or sodium acetate in the presence of a liquid aromatic compound. Thus 2-chlorodiphenyl is readily formed from o-chloro phenyl diazonium chloride and sodium hydroxide solution (or sodium acetate solution) in the presence of benzene ... 

First-order nitrations. The kinetics of nitrations in solutions of acetyl nitrate in acetic anhydride were first investigated by Wibaut. He obtained evidence for a second-order rate law, but this was subsequently disproved. A more detailed study was made using benzene, toluene, chloro- and bromo-benzene. The rate of nitration of benzene was found to be of the first order in the concentration of aromatic and third order in the concentration of acetyl nitrate the latter conclusion disagrees with later work (see below). Nitration in solutions containing similar concentrations of acetyl nitrate in acetic acid was too slow to measure, but was accelerated slightly by the addition of more acetic anhydride. Similar solutions in carbon tetrachloride nitrated benzene too quickly, and the concentration of acetyl nitrate had to be reduced from 0-7 to o-i mol 1 to permit the observation of a rate similar to that which the more concentrated solution yields in acetic anhydride. 

For the nine substituents m- andp-methyl, p-fluoro, m- and p-chloro, m- and p-bromo, and m- and p-iodo, using the results for nitration carried out at 25 °C in nitromethane or acetic anhydride - (see tables 9.1, 9.5), a plot of logjoA/ j against cr+ produced a substituent constant p = —6-53 with a standard deviation from the regression line i = 0-335, 2 correlation coefficient c = 0-975. Inclusion of... 

To a suspension of 7.5 mol of sodamide (see Chapter 11, Exp. 11) in 4.5-5 1 of liquid ammonia were added 2.0 mol of the chloro acetal in 30 equal portions with intervals of 2 min. Twenty minutes after this addition the stirrer was removed,... 

It is possible to prepare 1-acetoxy-4-chloro-2-alkenes from conjugated dienes with high selectivity. In the presence of stoichiometric amounts of LiOAc and LiCl, l-acetoxy-4-chloro-2-hutene (358) is obtained from butadiene[307], and cw-l-acetoxy-4-chloro-2-cyclohexene (360) is obtained from 1.3-cyclohexa-diene with 99% selectivity[308]. Neither the 1.4-dichloride nor 1.4-diacetate is formed. Good stereocontrol is also observed with acyclic diene.s[309]. The chloride and acetoxy groups have different reactivities. The Pd-catalyzed selective displacement of the chloride in 358 with diethylamine gives 359 without attacking allylic acetate, and the chloride in 360 is displaced with malonate with retention of the stereochemistry to give 361, while the uncatalyzed reaction affords the inversion product 362. 

The Curtms rearrangement has been used to prepare 5-aminothiazole (11) (60.61), 4-methyl-5-aminothiazole. 2-chloro-5-aminothiazole (58), and 2.4-dimethyl-5-aminothiazole (62) (Scheme 11). Heating the corresponding azides yield carbamates that resist hydrolysis but react with acetic anhydride to give the 5-acetylaminothiazoles. 

Acetamido-4-methylselenazole can react with mercuric acetate to yield 5-mercuriacetate derivatives that can be converted to the chloro derivatives by the action of sodium chloride. Treatment with potassium iodide leads to reduction regenerating the initial compound with loss of mercury (Scheme 16) (4). 

Arylamino-2-chloroprop-2- enoic esters (72) obtained from 2-chloroaceto acetic ester (71) and arylamines, react with thiourea to yidd substituted 2-aminothiazoles (73), probably by initial nucleophilic substitution of the chloro atom of 72, followed by cyclization with loss of aniline (Scheme 33) (729). 

Thiazole acetic acids and their hotnologs can also be prepared by cyclization procedures 4-thiazole alkanoic acids and their salts were prepared by treating a thioamide with a -y-chloro- or 7-bromoacetoacetic or their a-alkyl derivatives (4, 10, 16, 22, 273, 275, 281, 640, 647, 695). 

See also 4-Chloro-2-methylphenoxy acetic acid.) [PESTICIDES] (Vol 18)... 

---