Lawesson's reagent → 7-[(4,6-dimethoxy-pyrimidin-2-yl)oxy]-3-methyl-isobenzofuran-1(3H)-thione

Participants

Reaction Steps

A mixture of 6.35 g of 7-[(4,6-dimethoxy-pyrimidin-2-yl)oxy]-3-methyl-phthalide (see Example 1) and 8.92 g of 2,4-bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithia-diphosphetan (Lawesson reagent) is maintained at reflux temperature for approximately 16 hours in 40 ml of xylene. The reaction material is then filtered over silica gel (eluant: 30% diethyl ether/n-hexane) and recrystallised from ethyl acetate/n-hexane to yield 7-[(4,6-dimethoxy-pyrimidin-2-yl)oxy]-3-methyl-isobenzofuran-1(3H)-thione in the form of yellow crystals, m.p. 163°-164° C.; IR spectrum (CHCl3): 1602, 1570, 1358, 1304, 1195 cm-1 ; 1H-NMR (CDCl3): 5.80 ppm (q, 1H), 1.71 ppm (d, 3H).

Provenance & Evidence