Reaktion #50457

Reaktionsgleichung

7-hydroxy-3-methyl-phthalide

2,4-bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetan

→

7-hydroxy-3-methyl-isobenzofuran-1(3H)-thione

Lösungsmittel

xylene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturWhen it has cooled
2. 2
   Filtrationthe reaction material is filtered directly over a column of silica gel [eluant: ethyl acetate/n-hexane (1:4)] in order

Vorschrift

1.67 g of 7-hydroxy-3-methyl-phthalide (see Example 101) and 2.17 g of 2,4-bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetan (Lawesson reagent) are heated in 8 ml of xylene at 138° C. for 3 hours. When it has cooled, the reaction material is filtered directly over a column of silica gel [eluant: ethyl acetate/n-hexane (1:4)] in order to isolate the 7-hydroxy-3-methyl-isobenzofuran-1(3H)-thione; m.p. 38°-40° C.; IR spectrum: 1624, 1604, 1368, 1330, 1304, 1165 cm-1 ; mass spectrum: 180 (M+ =100), 165 (58), 137 (24).

Quelle