Methyl chloroacetate, condensation

The use of 4-bromo-3-formylthiophene (175) led to the third classical thieno[3,4-6]thiophene (8) via analogous reactions. The aldehyde (175) was protected by ketalization, and then subjected to bromine-metal exchange with n-butyllithium to give a lithio derivative which was reacted with sulfur, followed by methyl chloroacetate. The resulting ester-aldehyde derivative (176a) was condensed under the influence of base to give, after decarboxylation, thieno[3,4-6]thiophene (8 Scheme 61) <76AHC(19)123). 

Alternatively, 1-undecanal can be converted by aldol condensation with formaldehyde and subsequent hydrogenation into 2-methyl-undecanal (methyl-nonylacetaldehyde = MNA) [58]. This is a technically feasible alternative to the Darzens reaction of 2-undecananone with methyl chloroacetate. MNA is a sought-after principal ingredient in perfumery (see also Section 6.1.3.1.2). 

Similarly, ethyl (or methyl) a-formyl chloroacetate (69), Rj = H, and its substituted derivatives, condensed with thioformamide or higher thioamides give 5-ethyl- or 5-rnethyl-thiazole carboxylates (70) in good... 

Phenylisoxazolin-5-one condensed with anthranal to give a tricyclic isoxazolylquinoline (Scheme 72) <78CZ264). 3-Methyl-4-phenylazoisoxazoline-5-thione reacted with ethyl chloroacetate for form an intermediate isoxazolethiol, which on heating generated a 1,2,3-triazole (Scheme 73). 

The most simple surfactant betaines are alkyl betaines where one of the methyl groups of trimethyl glycine is replaced with a fatty alkyl moiety. Synthetically, they are made by condensing 1 mol of sodium chloroacetate with an alkyldimethylamine to yield the surfactant and 1 mol of sodium chloride by-product (see Figure 6.14). 

In our laboratory, a nucleophilic catalyst was used to conduct the condensation reaction. A typical reaction entailed heating five moles of dimethyl methylphosphonate with 11.2 moles of ethyl chloroacetate at 175 C in the presence of a catalytic amount of tetramethylammonium chloride catalyst. The reaction was followed by the amount of methyl chloride collected in a cold trap. After about eight hours, 9.7 moles of methyl chloride Is collected. After working up the product, 4.15 moles of tils methylphosphonate was isolated by distillation. 0.3 torr. the H-nmr spectrum was in... 

This reaction involves the condensation of an aldehyde or ketone with an a-halo ester in the presence of a basic condensing agent (sodium ethoxide, sodamide, finely divided sodium or potassium teri.-butoxide) to give a glycidic (or p-epoxy) ester. Thus acetophenone and ethyl chloroacetate yield phenyl-methyl glycidic ester (I) ... 

Here the alkyl part originates generally of coconut or tallow fatty acids. If methyl fatty acids or glycerides are the precursors, the liberated methanol is separated whereas glycerol is generally retained in the final product. Similar betainic structures, along with imidazoline-type amphoterics, occur as condensation products of fatty imidazolines and chloroacetic acid, as mentioned above. 

The VNS reaction of 4-nitroanisole with ethyl chloroacetate followed by the Knoevenagel condensation of the product with acetaldehyde affords a-(2-nitrophenyl)crotonate, which in the presence of f-BuOK in ferf-butanol undergoes cyclization into V-hydroxyindole-3-carboxylate (Scheme 76). Further alkylation of the latter compound with methyl iodide results in Af-methoxyindole. It is worth mentioning that in this reaction a partial loss of the alkene chain does happen to occur [194]. A similar phenomenon has been observed earlier in our laboratory [195]. 

Scheme 9 3- The condensation between ethyl chloroethanoate (ethyl chloroacetate, ClCH2C02Et) and ethanal (acetaldehyde, CH3CHO) in the presence of sodinm ethoxide (NaOCH2CH3) to produce the glycidic ester isomers ethyl (E)- and (Z)-3-methyl-2-carboxyoxirane.

E)-Chalcones 4 were prepared via Claisen-Schmidt condensation of methyl ketones with different aromatic aldehydes. Cycloaddition reaction of 4 with thiourea yielded the eorresponding thioxypyrimidine 5 derivatives. Compounds 5 were condensed with chloroacetic acid to yield thiazolopyrimidine 6. Also thione 5 were also condensed, in one pot reaction, with chloroacetic acid and aromatic aldehyde to yield arylmethylene derivatives 7 which could also be prepared directly by condensation of 5 with aromatic aldehydes (Scheme 2) [14-20]. 

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