Propionyl chloride, hydrolysis

In their original communication on the alkylation and acylation of enamines, Stork et al. (3) had reported that the pyrrolidine enamine of cyclohexanone underwent monoacylation with acid chlorides. For example, the acylation with benzoyl chloride led to monobenzoylcyclohexanone. However, Hunig and Lendle (33) found that treatment of the morpholine enamine of cyclopentanone with 2 moles of propionyl chloride followed by acid hydrolysis gave the enol ester (56), which was proposed to have arisen from the intermediate (55). 

Acylation of thiosemicarbazide with propionyl chloride, interestingly, does not stop at the acylated product (124). Instead, this intermediate cyclizes to the thiadiazole, 125, under the reaction conditions. Hydrolysis then affords the heterocyclic amine, 126. Acylation by 88 followed by removal qf the acetyl group affords sulfaethidole (116) variation of thle acid chloride used in the preparation of the heterocycle leads to 117 and 118. 

Oil-soluble derivatives of testosterone itself predate those of its 19-nor congener these agents too are used to administer depot injections so as to provide in effect long-term blood levels of drug. Thus, acylation of testosterone with propionyl chloride in the presence of pyridine yields testosterone propionate (76a)acylation by means of decanoic anhydride yields testosterone decanoate (76b).Finally, reaction of 75 with 3-cyclopentylpropionyl chloride affords testosterone cypionate (76c)This last undergoes hydrolysis unusually slowly because of the presence of two substituents at the 5 position (see Newman s Rule of 6). ... 

Although geneologically related to indoles, the dihydroindoles behave chemically rather like alkyl anilines. When diphenylamine reacts with chloro-propionyl chloride, amide 40 results this in turn readily cyclizes to oxindole 41. Sodium hydride followed by 2-chloroethyldimethylamine alkylates the 3-position (possibly through an intermediate aziridinium ion) partial demethylation is accomplished by refluxing with ethylchiorocarbonate, followed by hydrolysis of the intermediate carbamate to give indolinone 42, the antidepressant amedalin Repetition of this sequence on the chloropropyl homologue, followed by reduction of the appropriate indolinone produces dihydroindole 43, daledalin, which also has antidepressant activity. ... 

Condensation of prednisone, 40 with tetraethyl orthocarbonate leads to the cyclic orthocarbonate 41 hydrolysis proceeds by protonation on the most accessible ether oxygen (that on carbon 21) to give the 17 mixed carbonate ester 42, Acylation with propionyl chloride proceeds on the remaining hydroxyl group to afford prednicarbate (43) [10],... 

In 2002, Tagmatarchis et al. [152] reported the modification of SWCNTs through electrophilic addition of CHC13 in the presence of A1C13. From hydrolysis of the so-produced labile chlorinated intermediate species, hydroxy-functionalized SWCNTs were obtained, the coupling of which with propionyl chloride led to the corresponding SWCNT propionate esters (Scheme 1.17) [152],... 

In total synthesis of the structurally unique natural product calcimycin (15), Grieco and others used Ireland-Claisen rearrangement of the ester 17 to synthesize the key intermediate (18)7 (Scheme 1.3g). Monosilylation of the diol 16 followed by treatment with propionyl chloride in pyridine gave rise to the ester 17 in 90% yield. Treatment of 17 with LDA in THF at —78 C, subsequent addition of ferf-butyldimethylsilyl chloride in HMPA, and brief heating of the resulting silylketene acetal provided the corresponding silyl ester. Subsequent hydrolysis of the silyl ester and esterification with diazomethane gave 18 in 90% yield from 17. 

Preparation by hydrolysis of the corresponding propionic ester (SM) with sodium hydroxide in refluxing methanol for 1 h (quantitative yield) [7143]. SM was obtained by acylation of 4-methoxyphenyl propionate with propionyl chloride in nitromethane in the presence of stannic chloride at 20° for 48 h (56%). 

An electrophilic addition of chloroform to SWNTs was followed by hydrolysis and it resulted in the addition of hydroxyl groups to the surface of the nanotubes. Its esterification with propionyl chloride led to the corresponding ester derivatives (Tagmatarchis et al., 2002). 

The reactions of 0-naphthol and 4-methoxyphenol with acetyl, propionyl, butyryl, 0-chloropropionyl and chloracetyl chlorides in acetonitrile produce some striking kinetic results109. The behaviour of acetyl, propionyl and n-butyryl chlorides fit reasonably well into the pattern for acetyl chloride in nitromethane and acetyl bromide in acetonitrile. However, with chloracetyl chloride the mechanism is essentially a synchronous displacement of covalently bound chlorine by the phenol and this process is powerfully catalysed by added salt with bond breaking being kinetically dominant. When no added salt is present the rate of hydrolysis of chloracetyl chloride is ca. 8000 times slower than that of acetyl chloride. Although, normally, in second-order acylation reactions, substituents with the greatest electron demand have been found to have the fastest rates, the reverse is true in this system. Satchell proposes that a route such as... 

Acyl derivatives of perhydro-l,4-dioxopyrrolo[l,2-a]pyrazines are rapidly hydrolyzed to the 2-unsubstituted compounds under very mild conditions. The 2-pyruvoyl compound 86 loses the N-acyl group on boiling in water or methanol, on treatment with ammonia in methylene chloride, on exposure to dilute sodium hydroxide solution, and on treatment with p-toluidine at 50-60° for 30 sec. Similarly the methoxy-propionyl compound 142 is extremely sensitive to alkali, immediately reacting with 0.1 M sodium hydroxide solution at 0°. This compound is also deacylated by ammonium hydroxide solution in a few minutes or by sodium bicarbonate solution after several hours. This behavior contrasts sharply with that of the isomeric oxazolo compound 143 and helps to justify the tricyclic formulation adopted for such compounds. Hydrolysis of the 3S,8aS isomer of compound 142 is accompanied by rapid inversion... 

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