反应详情

3-Ethoxycarbonyl-1-methyl-1H-acenaphthyleno[1,2-c]pyrazole (2g), mp 107°-109° C., prepared according to Example 1 starting from acenaphthen-1-one, is dissolved in anhydrous tetrahydrofuran (45 ml) and added dropwise, under stirring, at a temperature varying between 10° C. and 20° C., to a solution of methylsulfinyl carbanion, obtained by reacting 50% sodium hydride (0.7 g) with anhydrous dimethylsulfoxide (30 ml) at 70° C. for 1 hour. The reaction mixture is kept under stirring at room temperature for 1 hour, then is diluted with ice water and acidified with citric acid to pH 4. The precipitate is extracted with ethyl acetate and the organic solution evaporated to dryness in vacuo. The residue is purified over a flash column using toluene/ethanol/diethylamine 100/10/1.5 as eluent. Washings with ethanol give 0.45 g of 1-methyl-3-methylsulfinylacetyl-1H-acenaphthyleno[1,2-c]pyrazole, mp 220°-230° C. dec., NMR (DMSOd6) δppm: 2.76 (s)(3H, --SOCH3), 4.16 (s)(3H, =N--CH3), 4.57 (s)(2H, --COCH2SO--), 7.5-8.70 (m) (6H, phenyl protons).

1. additionadded dropwise
2. customobtained
3. customat 70° C.
4. customfor 1 hour
5. stirringunder stirring at room temperature for 1 hour
6. extractionThe precipitate is extracted with ethyl acetate
7. customthe organic solution evaporated to dryness in vacuo
8. customThe residue is purified over a flash column
9. washWashings with ethanol