Methyl-2-furoate

Methyl 5,5-dimethoxy-3-metkyl-2,3-epoxypentanoate. A 2-1. three-necked flask is equipped with a sealed centrifugal stirrer (Note 1), a thermometer inserted through an adapter with a side arm connected to a source of dry nitrogen, and a 250-ml. Erlenmeyer addition flask.2 The apparatus is dried with a free flame in a slow stream of nitrogen from this point the reaction is conducted in an atmosphere of nitrogen (Note 2). 

A mixture of 132 g. (1.0 mole) of 4,4-dimethoxy-2-butanone (Note 3), 174 g. (1.6 moles) of methyl chloroacetate (Note 3), and 800 ml. of dry ether is placed in the reaction flask, then 86 g. (1.6 moles) of sodium methoxide (Note 4) is placed in the addition flask. The solution is cooled in an ice-salt bath to —10°, then the sodium methoxide is added gradually at a rate such that a temperature below —5° can be maintained (about 2 hours). 

Methyl 3-methyl-2-furoate. The crude glycidic ester prepared as described above is placed in a 300-ml. flask which is attached to a 12-cm. column filled with %6-inch glass helices (or a 50-cm. simple Vigreux column) and heated in a liquid bath. When the pot temperature reaches about 160°, or before, methanol begins to distil. Heating is continued until the distillation of methanol essentially ceases and about the theoretical amount (64 g.) has been collected. After the heating bath has been allowed to cool, the product is distilled at reduced pressure b.p. 72-78°/8 mm., yield 91-98 g. (65-70%) (Note 7). The ester solidifies in the receiver as an essentially pure compound, m.p. 34.5-36.5° (Note 8). 

A stirring assembly which makes use of a lubricated ball-joint seal3 is convenient. The checkers used a Hershberg stirrer rather than a centrifugal stirrer. 

Maintenance of a low positive pressure of nitrogen on the system is accomplished by insertion of a T-tube in the nitrogen line for attachment of a U-tube whose bend is just closed with mineral oil. 

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Oxidation of one molar proportion with sodium pieriodate produces two equivalents of formic acid, in accordance with the existence of hydroxyl groups attached to four contiguous carbon atoms. This oxidation (and also that carried out with lead tetraacetate) gives an aldehyde, whose semicar-bazone has an analysis corresponding to that of the semicarbazone of an ethyl formyl-methyl-furoate (XII). By oxidation of aldehyde XII with silver oxide in alkaline solution, 2-methyl-3,4-furandicarboxylic acid (XIV) was obtained this was identical with the compound described by Alder and Rickert.20 The identity was confirmed by preparation of the respective dianilides. The acid XIV has also been prepared by the reaction between the sodium salt of ethyl acetoacetate and ethyl bromopyruvate.9... 

Several other heterocyclic compounds have been used in the vinyl substitution. Quinones, for example, are readily substituted with a variety of heterocycles as well as with benzene.7 Heterocycles which react include 2-acetylfuran (5-position), furfural (5-position) (equation 5) methyl furoate (5-position), 2-ace-tylthiophene (5-position), N-benzenesulfonylpyirole (2-position), N-benzenesulfonylindole (3-position), 4-pyrone (3-position) and N-methyl-2-pyridone (3- and 5-positions). 

Oxa-3-azabicyclo[3.2.1]octan-2-one (65) derived from methyl furoate was allowed to polymerize in bulk with its N-acetyl derivative as the initiator, and... 

Maltol Isobutyrate 2-Methoxy 3-(or 5- or 6-) Isopropyl Pyrazine 5H-5-Methyl-6,7 -dihydrocyclopenta[b]pyrazine 5-Methyl Furfural Methyl Furoate Methyl Hexanoate Methyl Isovalerate 5-Methyl 2-Phenyl 2-Hexenal Methyl Thiobutyrate Methyl Valerate P-Naphthyl Ethyl Ether Phenyl Ethyl Cinnamate Phenyl Ethyl Propionate Propyl Formate Propyl Mercaptan Salicylaldehyde 8-T etradecalactone 2-Tridecanone... 

For 3-bromothiophene-2-aIdehyde (56), a long-range coupling-constant of 0.051 Hz was measured between H-4 and the aldehyde proton.175 From the peak widths of the / spectra, the value of T2 for the aldehyde proton was found to be 11.2 sec. Partial J spectra were obtained for this proton, and also for the ring protons of methyl furoate (57), by restricting the range of modulation frequencies... 

The intrinsically high reactivity of the furan nucleus is further exempUlied by the reaction of furfural with excess halogen to produce mucohalic acids incidentally, mucobromic acid reacts with formamide to provide a useful synthesis of 5-bromopyrimidine. On the other hand, with control, methyl furoate can be cleanly converted into its 5-monobromo or 4,5-dibromo derivatives hydrolysis and decarboxylation of the latter then affording 2,3-dibromofuran bromination of 3-furoic acid produces 5-bromofuran-3-carboxylic acid. ... 

Methyl furoate was found to react with 2,3-dimethylbutene-2 upon irradiation to give 183.213 Furan reacted with 2,5-diphenyl-1,3,4-oxadiazole upon irradiation, with or without a sensitizer, to yield cycloadduct 184.214... 

Methyl ester, C(H(Oj, methyl furoate, methyl pyromucate. 

Traditional Friedel-Crafts alkylation is not generally practicable in the furan series, partly because of catalyst-caused polymerisation and partly because of polyalkylation. Instances of preparatively useful reactions include production of 2,5-bis-t-butylfuran from furan or furoic acid ° and the isopropylation of methyl furoate with double substitution, at 3- and 4-positions. ... 

Methylfurfural 5-Methyl-2-furfural 5-Methylfurfuraldehyde. See Methylfurfural Methyl furoate. See Methyl 2-furoate Methyl 2-furoate... 

Synonyms Furan-a-carboxylic acid methyl ester 2-Furoic acid, methyl ester Methyl 2-furancarboxylate Methyl furoate Methyl pyromucate... 

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