Aroyl chloride

Substituted aroyl- and heteroaroyltrimethylsilanes (acylsilanes) are prepared by the coupling of an aroyl chloride with (Me3Si)2 without decarbonylation, and this chemistry is treated in Section 1.2[629], Under certain conditions, aroyl chlorides react with disilanes after decarbonylation. Thus the reaction of aroyl chlorides with disilane via decarbonylation is a good preparative method for aromatic silicon compounds. As an interesting application, trimel-litic anhydride chloride (764) reacts with dichlorotetramethyidisilane to afford 4-chlorodimethylsilylphthalic anhydride (765), which is converted into 766 and used for polymerization[630]. When the reaction is carried out in a non-polar solvent, biphthalic anhydride (767) is formed[631]. Benzylchlorodimethylsilane (768) is obtained by the coupling of benzyl chloride with dichlorotetramethyl-disilane[632,633]. 

Butyl vinyl ether reacts with aroyl chlorides using Pd(OAc)2 without a ligand to give the unsaturated ketone 839, which is a precursor of a 1-aryl-1,3-dicarbonyl compound. The reaction is regioselective /3-attack. Addition of PhjP inhibits the reaction[718]. 

The alkylphenylacetyi chloride 843 and benzoyl chloride undergo decarbo-nylative cross-condensation to give the enone 845 in the presence of EtiNf723]. The reaction is e.xplained by the insertion of the ketene 844 into the Pd-aryl bond and, 3-elimination. To support this mechanism, o, d-unsaturuted ketones are obtained by the reaction of ketenes with aroyl chlorides[724]. 

Various organotin reagents react with acyl and aroyl halides under mild conditions without decarbonylation to give carbonyl compounds[390,39l]. Alkyl- or alkenyltin reagents react with acyl and aroyl chlorides to give ketones[548.733,734]. One example is the preparation of the a,/3-dnsaturated 7-keto esters 860 and 861, carried out under a CO atmosphere[735]. The reaction has been applied intramolecularly to the synthesis of the macrocyclic keto... 

Preparation of Arylcarboxylic Acids and Derivatives. The general Friedel-Crafts acylation principle can be successfully appHed to the preparation of aromatic carboxyUc acids. Carbonyl haUdes (phosgene, carbonyl chloride fluoride, or carbonyl fluoride) [353-50-4] are diacyl haUdes of carbonic acid. Phosgene [75-44-5] or oxalyl chloride [79-37-8] react with aromatic hydrocarbons to give aroyl chlorides that yield acids on hydrolysis (133) ... 

Acylation of the heterocyclic enamines e.g., l,3,3-trimethyl-2-methyl-eneindoline (126) and 2-benzylidene-3-methylbenzothiazoline (42) takes place normally at the methylene carbon (42,69), with both acyl and aroyl chlorides in the presence of base. 

Acylation of mesoionic pyrido[l,2-u]pyrimidin-4-ones 150 with aroyl chlorides in the presence of NEts yielded 2-aroyloxy-4//-pyrido[l,2-u]pyrimidin-4-ones 178 (96JHC663). None of the esters 178 could be rearranged to the 2-hydroxy-3-aroyl derivatives 179. The hydroxy group of 9-hydroxy-2-methyl-3- 2-[4-(6-fluoro-l,2-benzisoxazol-3-yl)-l-piperidinyl] ethyl -6,7,8,9-tetrahydro-4//-pyrido[l, 2-u]pyrimidin-4-one was acylated with hexadecanoic acid in CH2CI2 in the presence of dicyclohexylcarbodi-imide and 4-pyrrolidinopyridine at room temperature for 3 days in 80% yield (97MIP7). 

Similarly, reaction of the bis(imino-/.5-phosphane) 4 with aroyl chlorides gives 1,3-benzodiazepines, which, however, were assigned the 1//-structures 5. < 3a-b... 

The bis(imino-A5-phosphane) 4 (0.508 g, 0.7 mmol) in CH2C12 (25 mL) was slowly treated with an aroyl chloride (0.7 mmol) and Et3N (0.07 g, 0.7 mmol) and the mixture was stirred at 20 C for 7 h. The solvent was removed in vacuo, benzene (15mL) was added, the precipitated Et3N HC1 was filtered off and the filtrate was evaporated under reduced pressure. Chromatography of the residue (silica gel, EtOAc/hexane 1 2) gave the red product, which was recrystallized (EtOH). 

Aroylation of 3-arylhydrazonoisatin with aroyl chlorides gave 1043, which cyclized with ammonium acetate to give [1,2,4]triazino[5,6-A>]indole 1044 (92MI1). Derivatives of 1045 were prepared (92MI1). Cyclocondensation of 5-ethyl-3-hydrazino-5/f[l,2,4]triazino[5,6-b]indole 165 with succinic anhydride in acetic acid gave pyridazinedione derivative 1046 (90MI7) (Scheme 197). 

Use of 2,4,6-trichlorobenzoyl chloride, Et3N, and DMAP, known as the Yamaguchi method,128 is frequently used to effect macrolactonization. The reaction is believed to involve formation of the mixed anhydride with the aroyl chloride, which then forms an acyl pyridinium ion on reaction with DMAP.129... 

This novel resin-bound CHD derivative was then utilized in the preparation of an amide library under microwave irradiation. Reaction of the starting resin-bound CHD with an acyl or aroyl chloride yields an enol ester, which, upon treatment with amines, leads to the corresponding amide, thus regenerating the CHD. This demonstrates the feasibility of using the CHD resin as a capture and release reagent for the synthesis of amides. The resin capture/release methodology [126] aids in the removal of impurities and facilitates product purification. 

Electroluminescent phenantroline dyes containing triphenylamine and 1,3,4-oxadiazole fragments were prepared using tetrazole-oxadiazole interconversion performed in the presence of aroyl chlorides <2004TL6361>. Also, iV-tributylstannyltetrazoles treated with acetic anhydride gave oxadiazole derivatives <2002RCB357>. 

The synthesis of 1,2,3-selenadiazole derivatives has been reported. The reaction of aroyl chlorides such as 102 with potassium isoselenocyanate and ethyl diazoacetate yielded 5-(aroylimino)-2,5-dihydro-l, 2,3-selenadiazole-4-carboxylate esters such as 104. A reaction mechanism via the initial formation of the corresponding aroyl isoselenocyanate 103 followed by a 1,3-dipolar cycloaddition of the diazo compound with the C=Se bond is proposed <00HCA539>. 

Bakavoli et al. have synthesized new 3-substituted [l,2,4]triazolo[3, 4 2,3][l,3]triazolo[4,5- ]quinoxalines by the cyclocondensation of [l,3]thiazolo[4,5- ]quinoxaline-2(3//)-one hydrazone with aroyl chlorides, trimethylorthofor-mate, or triethylorthoacetate H NMR data are provided <2006PS(111)99>. 

Friedel-Crafts methods7 and the reaction of aroyl chlorides with 2-pyrrolidinone8 have been described. There is also a useful procedure, similar to the one presented here, that employs N-trimethylsilylpyrrolidin-2-one.9... 

The reaction of sodium azide with N-aryl chloroimines, obtained from benzanilides and thionyl chloride, to form 1,5-disubstituted tetrazoles is catalysed by tetra-n-butyl-ammonium bromide (Scheme 5.26, Table 5.40) [18] in variable yields, but generally <85%. 5-Butyl-2,3-diphenyltetrazolium salts have also been used as catalysts [18, 19]. 1,5-Disubstituted tetrazoles are also obtained from a one-pot sequential reaction of carbodimides with sodium azide and an aroyl chloride in the presence of tetra-n-butylammonium chloride [20]. 5-Chlorotetrazoles are obtained from the catalysed reaction of aryldichloroisocyanides with sodium azide (Scheme 5.26) [21],... 

The aroyl chloride (10 mmol) in PhMe (10 ml) is added dropwise to the carbodiimide (10 mmol), NaN (975 mg, 15 mmol) and TBA-Cl (0.28 g, l mmol) in PhMe (40 ml) at room temperature under N2. After ca. 3-4 h, the mixture is heated to 95 °C for 30 min. The cooled mixture is filtered and evaporated under reduced pressure to yield the tetra-zole, which is purified by chromatography from silica [e.g. 64% from PhN=C=NPh and PhCOCl 55% from TolN=C=NTol and PhCOCl 70% from PhN=C=NPh and TolCOCI],... 

The facile homogeneous catalysed reduction of acid chlorides to alcohols has many advantages over reduction with sodium borohydride in hydroxylic solvents where rapid reaction of the acid chloride with the solvent can occur [10]. The procedure has been incorporated into a simple one-pot conversion of aroyl chlorides into the corresponding benzyl chlorides (Scheme 11.1) under liquidrliquid or solid-liquid two-phase conditions [11], The reduction of a limited number of aryl compounds was reported with ca. 70% overall yields, although poorer yields result from the reduction of 4-nitro-, 2-cyano- and 2,4-dichlorobenzoyl chlorides, and the reduction failed completely with terphthaloyl chloride and with its 2,3,5,6-tetrafluoro derivative [11]. 

The combination of [IrCl(cod)Cl]2 complex with P(t-Bu)3 efficiently catalyzes aromatic homologation using internal alkyne [70]. For example, the reaction of benzoyl chloride 153 with 4-octyne 154 afforded 1,2,3,4-tetrapropylnaphthalene 155 (Equation 10.41). The reaction with 2-thenoyl and 2-naphthoyl chlorides also affords benzothiophene and anthracene, respectively, in high yields. The reaction would proceed as follows (Scheme 10.9) (i) oxidative addition of aroyl chloride... 

Benzocondensed 3,l-oxazin-4-ones are also accessible via an aza-Wittig reaction (Scheme 86) (93T581). Iminophosphorane 230 affords an imidoyl chloride with aroyl chlorides. The electrophilic C atom is attacked by the ester methoxy group, and the formation of a six-membered ring 231 is thermodynamically favored. Extrusion of methyl chloride gives the stable benzoxazinone 232 (93T581). 

A novel heterocyclic system has been achieved from methyl 3-aminopyra-zine-2-carboxylate and several aroyl chlorides, leading to 3-aroylamino derivatives the latter are cyclized with dibromotriphenylphosphorane to 2-arylpyrazino[2,3-rf][3,l]oxazin-4-one (94S405). Furthermore, vinylimino-phosphoranes and diphenylketene react (Scheme 87) to give nonisolable vinylketenimines (233) which afford, with a second equivalent of ketene in a [4 + 2]-cycloaddition, 1,3-oxazinones (234) [89JCS(P1)2140]. 

Schmidt showed that reaction of 1 mole of aroyl chloride with 2 moles of an aryl nitrile in the presence of stannic or zinc chloride afforded in excellent yields a 2,4,6-triaryldiazapyrylium salt (109) in which at least two of the aryl groups (at positions 2 and 4) were alike. It was presumed that the intermediate was an aroylnitrilium ion (108). 

The reduction of aroyl chlorides take a different course in the presence of Ni(ll) salts. Reaction is best effected in an undivided cell with a nickel anode and a nickel foam cathode with acetonitrile containir tetrabutylammonium fluoroborate as electrolyte. Symmetrical ketones are formed [173], Substimted benzoyl chlorides yield the benzophenone in 47-72% yields. Phenacetylchloride also gives the ketone in good yield but in general, alkanoyl chlorides do not react. 

There are many heterocyclic molecules in which 1,3,4-thiadiazoles are fused to other ring systems. For example, Molina et al. developed a procedure for building a thiadiazole ring on to a properly substituted imidazole moiety (Scheme 29). Reaction of l-amino-2-methylthio-4-phenylimidazole (161) with triphenylphosphine dibromide in dry benzene furnished the 2-methylthio-4-phenyl-l-triphenylphosphoranylidenamino imidazole (162) in a 95% yield. With aroyl chlorides at elevated temperature, this gave the 2-aryl-6-phenylimidazo[2,l-Z ][l,3,4]thiadiazoles (164) in yields between 50% and 70% via the imidoyl chloride intermediate (163) which could be isolated and shown to cyclize to the thiadiazole. The method developed for the imidazole ring was also applicable to the thiadiazolotriazine ring system <88H(27)1935). 

The oxathiazoline derivatives (200), are obtained by electrocyclization of the thione S-imide intermediates (201), which are formed either from the S,S-dibenzylsulfur diimides (202) and excess of aroyl chlorides (R = Ar, = H) <74ZN(B)284>, or by base treatment of N-acyl chlorodiaryl methane sulfenamides (203 R R = Ph or fluorenyl residue) (Scheme 38) <74JOC2885>. 

Iminophosphoranes derived from readily available ot-azidocinnamates react with aroyl chlorides to give the corresponding 2-aryl-4-arylidene-5(4//)-oxazolones 37 2 500,501 AjteiTjatively, these iminophosphoranes are converted to the corresponding 2-arylamino-4-arylidene-5(4//)-oxazolones 373 via heterocyclization of an intermediate carbodiimide as shown in Scheme 7.119 (Table 7.32, Fig. 7.43). ° ... 

A number of recent papers have appeared in the literature related to the synthesis of saturated 5(477)-oxazolones that were not yet covered in our contribution. 4-Acyl-2,4-dialkyl-5(477)-oxazolones 776 have been obtained from A-acylglycines. Thus, cyclization of an A-acylglycine in the presence of thionyl chloride affords a monosubstituted 5(477)-oxazolone 775. Acylation of 775 with an aroyl chloride in the presence of magnesium chloride occurred at C-4 to produce 776. Hydrolysis and decarboxylation of 776 gave the A-acylamino ketones 777 that are valuable intermediates to prepare oxazoles 778 (Scheme 7.236). 

Acylation of (S)-2-pyrrolidinemethanol (1) with aroyl chlorides provides amides 2 which, when treated with base and iodomethane or chloro(methoxy)methane, furnish the corresponding methyl or methoxymethyl ethers 3. 

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