反应详情

温度

-70 °C

In a sulfonation flask, 7.8 g (0.039 mol) N-(2-bromophenyl)formamide was dissolved in a mixture of 150 ml dry tetrahydrofuran and 150 ml dry diethyl ether. The solution was cooled to −70° C. and 25.6 ml (0.041 mol) methyllithium solution (1.6M in diethyl ether) added in 30 minutes in such a manner that the internal temperature remained constant at −70° C. Then the resulting solution was cooled to −100° C. and 25.6 ml (0.041 mol) of n-butyllithium solution (1.6M in hexane) was added in such a manner that the internal temperature remained constant at −100° C. (±2° C.). After stirring for 2 hours at −70 to −75° C., the solution was again cooled to −100° C. and 4.54 g (0.041 mol) 2-cyclopropylcyclobutan-1-one (prepared as described in Example 2) dissolved in 30 ml of dry tetrahydrofuran, was added slowly (20 minutes) at an internal temperature of −100° C. After stirring for 3 hours at −75° C., the temperature was elevated to 0° C. in ca. 30 minutes. After the addition of concentrated ammonium chloride solution, ethyl acetate was added and the organic phase was washed several times with water. After drying and evaporation of the solvent in a water jet vacuum, the crude material was obtained. Purification was achieved by flash chromatography over silica gel (eluant: hexane/ethyl acetate 1:1). Yield: 3.4 g (38% of theory) of N-[2-(2-cyclopropyl-1-hydroxycyclo-butyl)-phenyl]formamide in the form of a slightly yellow liquid.

1. customremained constant at −70° C
2. temperatureThen the resulting solution was cooled to −100° C.
3. customremained constant at −100° C.
4. custom(±2° C.)
5. temperaturethe solution was again cooled to −100° C.
6. additionwas added slowly (20 minutes) at an internal temperature of −100° C
7. stirringAfter stirring for 3 hours at −75° C.
8. waitthe temperature was elevated to 0° C. in ca. 30 minutes
9. additionwas added
10. washthe organic phase was washed several times with water
11. customAfter drying
12. customevaporation of the solvent in a water jet vacuum