Reaction of diethyl bromomalonate with sodium phenoxide

A Strategy to Avoid Anomalous O‐Alkylation of 4‐Hydroxyindole by Diethyl Bromomalonate.

“…Several aryloxymalonates are known and have normally been prepared by alkylation of the appropriate phenol with a halomalonate ester [3,4]. Formation of diaryloxymalonates has also been observed as a significant by-product in such reactions, along with products formed by dimerization of the halomalonate [3,4]. Application of this reaction with 4hydroxyindole gave further unexpected complexities and we describe these results here, together with a means to synthesize 3 without unwanted side reactions.…”

“…As an early intermediate in this projected synthesis, we required the indolyloxymalonate 3. Several aryloxymalonates are known and have normally been prepared by alkylation of the appropriate phenol with a halomalonate ester [3,4]. Formation of diaryloxymalonates has also been observed as a significant by-product in such reactions, along with products formed by dimerization of the halomalonate [3,4].…”

The reaction of hydroquinone and monosubstituted hydroquinones with dimethyl chloromalonate

“…Of the other aromatic phenols studied, 9-methoxyphenol, a-naphthol, p-naphthol, resorcinol, and catechol gave only O-alkylated products, as did phenol itself . 3 The reactions which resulted in C-alkylation were generally characterised by a pronounced colow change, mild exothermicity, and (other than that of t-butylhydroquinone) a heavy precipitate a t the end of the reaction, after partial removal of the solvent (see Experimental section). In all these reactions the hydroquinone species was treated with 0.5 equiv.…”

New furan and dihydro-4-pyrone synthesis via Diels-Alder reactions between methyl 2-[2'-acetamido-4'(1'H)-pyrimidon-6'-yl]glyoxylate and diethyl oxomalonate and oxygenated 1,3-dienes

“…Reaction (see procedure for 15 above) of 42.3 g (0.110 mol) of 14 with 22.4 g (0.130 mol) of guanidine carbonate afforded 24.0 g of crude 16, mp 210-216 °C. Recrystallization from EtOH-water afforded the analytical specimen of 16 as white plates: mp 239-241 °C; NMR (Me2SO-de) 5.88 (s, 1), 6.41 (s, 1), 6.75 (bs, 2), 6.9-7.S (m, 10), 10.95 (bs, 1).…”