Reaction with acetyl chloride

Reduction of a nitro compound to a primary amine. In a 50 ml. round-bottomed or conical flask fitted with a reflux condenser, place 1 g. of the nitro compound and 2 g. of granulated tin. Measure out 10 ml. of concentrated hydrochloric acid and add it in three equal portions to the mixtiue shake thoroughly after each addition. When the vigorous reaction subsides, heat under reflux on a water bath until the nitro compound has completely reacted (20-30 minutes). Shake the reaction mixture from time to time if the nitro compound appears to be very insoluble, add 5 ml. of alcohol. Cool the reaction mixture, and add 20-40 per cent, sodium hydroxide solution imtil the precipitate of tin hydroxide dissolves. Extract the resulting amine from the cooled solution with ether, and remove the ether by distillation. Examine the residue with regard to its solubility in 5 per cent, hydrochloric acid and its reaction with acetyl chloride or benzene-sulphonyl chloride. 

The ability to promote /S elimination and the electron-donor capacity of the /3-metalloid substituents can be exploited in a very useful way in synthetic chemistry. Vinylstannanes and vinylsilanes react readily with electrophiles. The resulting intermediates then undergo elimination of the stannyl or silyl substituent, so that the net effect is replacement of the stannyl or silyl group by the electrophile. An example is the replacement of a trimethylsilyl substituent by an acetyl group by reaction with acetyl chloride. 

Acetamido-2-deoxy-D-glucose, reaction with acetyl chloride, 46,1... 

The chiral acetate reagent is readily prepared from methyl mandelate [methyl (A)-hydroxy-phenyl acetate] which is first converted by treatment with phcnylmagnesium bromide into the triphenylglycol783, c (see Section 1.3.4.2.2.2.) and subsequently transformed into the acetate by reaction with acetyl chloride in the presence of pyridine. Thereby, the secondary hydroxyl group of the glycol is esterified exclusively. Both enantiomers of the reagent are readily accessible since both (R)- and (5)-hydroxyphenylacelic acid (mandelic acids) arc industrial products. 

Using 1,2-dichloroethane as solvent, Brown et al. 16 have also studied the acetylation reaction, with acetyl chloride and aluminium chloride as reagents at 25 °C. The appropriate data for benzene are given in Table 111 and by comparison with Table 109 it appears that acetylation occurs some 300 times as fast as benzoylation. 

As previously discussed, solvents that dissolve cellulose by derivatization may be employed for further functionahzation, e.g., esterification. Thus, cellulose has been dissolved in paraformaldehyde/DMSO and esterified, e.g., by acetic, butyric, and phthalic anhydride, as well as by unsaturated methacrylic and maleic anhydride, in the presence of pyridine, or an acetate catalyst. DS values from 0.2 to 2.0 were obtained, being higher, 2.5 for cellulose acetate. H and NMR spectroscopy have indicated that the hydroxyl group of the methy-lol chains are preferably esterified with the anhydrides. Treatment of celliflose with this solvent system, at 90 °C, with methylene diacetate or ethylene diacetate, in the presence of potassium acetate, led to cellulose acetate with a DS of 1.5. Interestingly, the reaction with acetyl chloride or activated acid is less convenient DMAc or DMF can be substituted for DMSO [215-219]. In another set of experiments, polymer with high o -celliflose content was esterified with trimethylacetic anhydride, 1,2,4-benzenetricarboylic anhydride, trimellitic anhydride, phthalic anhydride, and a pyridine catalyst. The esters were isolated after 8h of reaction at 80-100°C, or Ih at room temperature (trimellitic anhydride). These are versatile compounds with interesting elastomeric and thermoplastic properties, and can be cast as films and membranes [220]. 

Aromaticity of 2,4,6-tri-fert-butylphenylphosphole (17d) was also revealed in chemical reactions phosphole 17d could undergo aromatic electrophilic substitution. In reaction with acetyl chloride, a mixture of 2-, 4-, and 5-acetyl phospholes (23a, 24a, and 25a, respectively), as well as a diacetyl derivative (26a) were formed (Scheme 6) [39], Interestingly, the most crowded 2-acetyl derivative (23a) was the main product of the Friedel-Crafts reaction. A similar situation was observed for 3-methylpyrrol [46],... 

The reaction with acetyl chloride affords the diagonal methyl derivative after CO deinsertion, as in the case of Mel (Scheme 17) ... 

Finally, Lecomte and coworkers reported the synthesis of mikto-arm star-shaped aliphatic polyesters by implementing a strategy based on click chemistry (Fig. 36) [162]. Firstly, the polymerization of sCL was initiated by a diol bearing an alkyne function. The chain-ends were protected from any further undesired reaction by the esterification reaction with acetyl chloride. The alkyne was then reacted with 3-azidopropan-l-ol. The hydroxyl function located at the middle of the chain was then used to initiate the ROP of sCL and y-bromo-s-caprolactone. Finally, pendant bromides were reacted successfully with sodium azide and then with N, N-dimethylprop-2-yn-l-amine to obtain pendant amines. Under acidic conditions, pendant amines were protonated and the polymer turned out to exhibit amphiphilic properties. 

Reaction with acetyl chloride yields diacetyl peroxide. Similar diacyl peroxides are formed from other acyl chlorides ... 

An intramolecular cycloaddition brought about by reaction with acetyl chloride and di-isopropylamine converted the imine 377, presumably via 378, to a mixture of the carbazole 379 and the tetracycle 380 prolonged heating alone or brief treatment of the latter with p-toluenesulfonic acid caused elimination and the formation of 379. ... 

In a modern version of well-established Af-oxide chemistry, l,3-dimethyllumazine-5-oxide was converted into the corresponding 6-triflate using trifluoromethanesulfonic anhydride thereby opening the way to many reactions mentioned in Section 10.18.7.2 <1997PTR1> <2002H(57)1841>. Similar reactions with acetyl chloride and acetyl bromide afforded the corresponding 6-chloro- and 6-bromolumazines. 

A benzofuran ring replaces one of the benzene rings of the biphenyl moiety present in many of the sartans in the rather more complex drug saprisartan (80-10). It is of note, further, that the acidic proton is provided in this case by a trifluorosulfo-namide instead of the more common tetrazole ring. Construction of the imidazole fragment begins by nitrosation of the (3-ketoester (79-1) by means of sodium nitrite in acid to afford the oxime (79-2). Reaction with acetyl chloride leads to the ester (79-3). Reaction of this last intermediate with the iminoether from propionitrile then affords the imidazole (79-4). 

Propargyltrimethylsilanes are converted into 3-alkyl-3-halo-l,2-dienes by iodine or bromine. Reaction with acetyl chloride and AlClj results in a 3-acelyl-3-alkyl-l,2-dicnc, but in low yield. ... 

The sulfoxide derivatives of some thiabenzenes have been prepared these molecules are much more stable than the parents, and may be subjected to a wider range of reactions (Scheme 26) (74JOC3519). It is apparent that the ylidic character of these molecules is reduced vis-a-vis the non-oxygenated species. The lack of reaction with acetyl chloride should be compared with the effect of trimethylsilyl chloride in equation (72) (74JA6119). The mechanism of this reductive dealkylation has not been explored. 

Tetrahydrobenzo[ ]thiophene behaves like thiophene in electrophilic substitution reactions. Thus, it is formylated with a mixture of vV-methylformanilide and phosphorus oxychloride,436 iodinated in the presence of mercuric oxide,193 and brominated by V-bromosuccinimide,193 all in the 2-position in Friedel-Crafts reactions with acetyl chloride,194-436 propionyl chloride,436 succinic... 

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