Hydrochloric Acid → 3',4'-Dichloropropiophenone

温度

0 °C

Tetrahydrofuran, 75 mL, was cooled to 0° C., and 10.3 mL of methylmagnesium iodide (3.0M in diethyl ether) was added dropwise during a 30 minute period. The reaction mixture was maintained at <2° C. during the addition. Upon completion of addition, 7.0 grams (0.028 mole) of N-methoxy-N-methyl-3,4-dichlorophenylacetamide was added dropwise during a 45 minute period. The reaction mixture temperature was maintained between -2° C. and +2° C. throughout the addition. Upon completion of addition, the reaction mixture was stirred at about 0° C. for 1.5 hours. After this time, 50 mL of aqueous 2N hydrochloric acid was added dropwise to the reaction mixture. The reaction mixture temperature was maintained at <4° C. throughout the addition. The reaction mixture was then taken up in 100 mL of water and extracted with two 150 mL portions of diethyl ether. The combined extracts were washed with 100 mL of an aqueous solution saturated with sodium chloride. The extracts were then dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue, which weighed 6.6 grams. The 6.6 grams isolated here was combined with 3.2 grams of the same material prepared in an analogous manner. The combination was subjected to column chromatography on silica gel. Elution was accomplished using 50% methylene chloride in petroleum ether, then gradually increasing to 75% methylene chloride in petroleum ether. The product-containing fractions were combined and concentrated under reduced pressure, yielding 3.4 grams of (3,4-dichlorophenyl)acetone. The NMR spectrum was consistent with the proposed structure.

1. temperatureThe reaction mixture was maintained at <2° C. during the addition
2. additionwas added dropwise during a 45 minute period
3. temperatureThe reaction mixture temperature was maintained between -2° C. and +2° C. throughout the addition
4. additionUpon completion of addition
5. temperatureThe reaction mixture temperature was maintained at <4° C. throughout the addition
6. extractionextracted with two 150 mL portions of diethyl ether
7. washThe combined extracts were washed with 100 mL of an aqueous solution saturated with sodium chloride
8. dry with materialThe extracts were then dried with magnesium sulfate
9. filtrationfiltered
10. concentrationThe filtrate was concentrated under reduced pressure to a residue, which
11. customThe 6.6 grams isolated here
12. customprepared in an analogous manner
13. washElution
14. temperaturegradually increasing to 75% methylene chloride in petroleum ether
15. concentrationconcentrated under reduced pressure

ORDレコード

ord-2d56753b7a274ef89f57768352c0cf2c

出典データセット

uspto-grants-1997_06

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05639753