Alkyl Carbonates in Synthetic Chemistry. I. Condensation with Organic Esters. Synthesis of Malonic Esters¹

Abstract

Compared to other simple organic esters, the alkyl carbonates have found little application in synthetic reactions. This is the first of several papers reporting investigations which greatly extend the uses of this interesting class of compounds. Scattered through the literature may be found a few instances in which alkyl carbonates have been employed but none of these suggests a type reaction of broad applicability or utility.The present paper describes a method of condensing alkyl carbonates with organic esters to produce malonic esters. The new synthesis of

On the hydrolysis of diethyl 2-(perfluorophenyl)malonate

“…At the same time, diethyl 2-(perfluorophenyl)malonate ( 3 ) is a readily accessible compound. Diethyl 2-phenylmalonate ( 4 ) is usually obtained ( Scheme 1 ) by condensation of ethyl phenylacetate ( 5 ) and diethyl carbonate under basic conditions [ 22 ] because of the low reactivity of bromobenzene in noncatalytic nucleophilic reactions with sodium salts of diethyl malonate ( 6 ) [ 23 – 24 ].…”

Pteridines. XXVIII. New, general, and unequivocal pterin synthesis

“…Reaction of 2-amino-3-carbamoyl-5-phenylpyrazine 1-oxide with ethyl chloroformate in xylene solution, as described above, gave 2-ethoxycarbonylamino-3-carbamoyl-5-phenylpyrazine 1-oxide (8b) (84% yield), which was cyclized to 6-phenyllumazine 8-oxide by heating with sodium methoxide in methanol: yield, 90%, mp >320°; nmr (CFsCOOH) 7. 30 (3, m), 8.00 (2, m, C6-C6H5), 8.93 (1, s, Cr-H); uv X"2°nm…”

“…We therefore attempted to repeat the potentiometric titration on a very pure sample of 2,2,6,6-tetramethylpiperid-4-one N-oxyl. 30 There was no break in the titration curve from pH 8 to 2 and the nitroxide still gave a strong epr signal. It must be concluded that Rozantsev and Gintsberg titrated an impurity.…”

Synthesis of Carbonate Esters by Carboxymethylation Using NaAlO2 as a Highly Active Heterogeneous Catalyst

“…Scheme 1A). [6] To address these issues, a greener alternative is the carboxymethylation reaction using (i) environmental friendly reagents and (ii) heterogeneous catalysts.…”

“…Unfortunately, the currently applied routes toward these chemicals rely on toxic reagentse.g. chloroformates, trimethylamine, pyridine, phosgeneand on the use of homogeneous catalysts, which are non-reusable and require onerous separation procedures (Scheme A) . A greener alternative would be carboxymethylation reactions using (i) environmentally friendly reagents and (ii) heterogeneous catalysts.…”