Reactions with mercaptans. V. Action of aromatic thiols on furocoumarins, furochromones, and 2-aralkylidene-3(2H)-thianaphenone 1,1-dioxides was written by Asker, Wafia;Shalaby, Ahmed F. A. M.;Zayed, Salah M. A. D.. And the article was included in Journal of Organic Chemistry in 1958.Synthetic Route of C10H8O3 This article mentions the following:
In conjunction with the study of the pharmacol. action of S-containing compounds, it was found that xanthotoxin (I, R = OMe, R’ = H) (II) treated with PhSH and 4-MeC6H4SH (III) in the presence of piperidine (IV) gave addition products, V (Ar = Ph) (VI) and V (Ar = C6H4Me-4) (VII), resp. Other ring compounds were treated similarly. Thiol adducts: General procedure. The compound under investigation (0.5 g.), 0.5 g. aromatic thiol, and a few drops freshly distilled IV warmed 10 hrs. on a steam bath in case of II, the mixture cooled, washed with petr. ether, and crystallized gave 80% VI, m. 132° (EtOH), and 72% VII, m. 136° (EtOH). O2S.C-(:CHAr).CO.C:C.CR”:CR’.CR:CH (VIII) were prepared by the condensation of 3(2H)-thianaphthenone 1,1-dioxides with BzH (method of Mustafa and Z., loc. cit.). The following VIII were prepare (R, R’, R”, Ar, reaction temperature, m.p., % yield given): Me, H, H, Ph (IX), 150°, 209° (AcOH), 92; H, Me, H, Ph (X), 160°, 210° (AcOH), 78; H, H, Me, Ph (XI), 60°, 158° (EtOH), 75; H, H, Cl, Ph (XII), 170°, 216° (AcOH), 85; H, H, H, C6H4OMe-4, 150°, 165° (EtOH), 71. VIII were condensed with PhSH and III by heating 3 hrs. at the stated temperature in the absence of a catalyst to give the following thiol adducts, O2S.CH(CHAr)(SAr’).CO.C:C.CR”:CR’.CR:CH (VIII used, Ar’, reaction temperature, m.p. % yield given): IX, Ph (XIII), 100°, 116° (C6H6-petr. ether), 85; IX, C6H4Me-4, 130°, 156° (C6H6), 82; X, Ph, 120°, 155° (C6H6), 79; X, C6H4Me-4, 130°, 182° (C6H6), 76; XI, Ph, 100°, 137° (C6H6), 92; XI, C6H4Me-4, 100°, 135° (C6H6-petr. ether), 91; XII, Ph, 120°, 150° (C6H6), 87. VI (1 g.) and 100 ml. 4% alc. KOH refluxed 4 hrs. and worked up gave 0.25 g. PhSH as the Pb salt and 0.5 g. II. XIII (0.2 g.) heated 20 min. in a bath kept at 140°, cooled, and the product crystallized (EtOH) gave IX. I (R’ = H, R = OCH2CH:CMe2), and PhSH (equimolar amounts), and a few drops IV heated 3 hrs. in an oil bath kept at 155-60°, the mixture cooled, washed with petr. ether, and the resulting solid crystallized (C6H6) gave 85% I (R’ = H, R = OH), m.p. and mixed m.p. 233°. I (R’ = OMe, R = H), coumarilic acid, or its Me ester failed to react with PhSH in the presence of IV. Khellin [XIV (R = R’ = OMe)] (XV) (1 g.), 2 g. PhSH, and a few drops IV heated 3 hrs. at 100° and worked up gave 0.8 g. XIV (R’ = OMe, R = OH) (XVI), m. 204°. XV treated with III as above also gave XVI. XIV (R’ = H, R = OMe) treated with PhSH as above gave XIV (R’ = H, R = OH), m. 155°. XVI (0.5 g.) in 30 ml. dry Et2O and 2 ml. MeOH treated with Et2O-CH2N2 (from 4 g. nitrosomethylurea), kept 24 hrs. in an ice chest, treated again with the same amount Et2O-CH2N2, kept 48 hrs. at 0°, the solid collected (the Et2O solution allowed to evaporate slowly yielded addnl. material), and crystallized (dilute MeOH) gave XV, m. 153°. In the experiment, the researchers used many compounds, for example, Methyl benzofuran-2-carboxylate (cas: 1646-27-1Synthetic Route of C10H8O3).
Methyl benzofuran-2-carboxylate (cas: 1646-27-1) belongs to benzofurans derivatives. Benzofurans are compounds with a planar structure having 10 pi electrons that include the lone pair on oxygen atom, which makes it more susceptible to electrophilic attack. As benzofurans are prone to undergo ring opening of the heterocycle, examples of reduction of this type of aromatics by using dissolving metals are rather scarce.Synthetic Route of C10H8O3
Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem