反应详情

A suspension of isochroman-3,4-dione 4-oxime (90.4 HPLC-area %, 145.8 g, 0.74 mol) and potassium carbonate (153.4 g, 1.11 mol) in toluene (1000 mL) was stirred at ambient temperature for 1 h before dimethylsulfate (141.4 g, 1.11 mol) was added dropwise at 26° C. over a period of 2.5 h. The resulting mixture was stirred for 24 h at ambient temperature. After completion of the reaction, dist. water (1000 mL) was added to the mixture under stirring. The organic layer was separated, washed with dist. water (500 mL) and dried in vacuo at 30-50 mbar and max. 50° C. Isochroman-3,4-dione 4-(O-methyl-oxime) was obtained as a light orange solid (160.1 g, 88.7 HPLC-area %, quant. yield, diastereomeric ratio=58:42).

1. additionwas added dropwise at 26° C. over a period of 2.5 h
2. customAfter completion of the reaction, dist
3. stirringunder stirring
4. customThe organic layer was separated
5. washwashed with dist
6. dry with materialwater (500 mL) and dried in vacuo at 30-50 mbar and max
7. custom50° C