反应详情

About 8.7 ml of bromobenzene in 20 ml. of dry ether were added to a stirred suspension of 1 g. lithium shavings in 50 ml. of dry ether under a nitrogen atmosphere over a period of 30 minutes. This rate of addition was sufficient to maintain the reaction at a gentle reflux. After the addition, the mixture was stirred for 1.5 hours, followed by the addition of 18.9 g. of 2-(3,4-dimethoxyphenyl)-2-(6-methyl-2-pyridyl)-1,3-dioxane which was dissolved in the minimum quantity of dry tetrahydrofuran. Eight g. of benzyl chloride in 10 ml. of dry tetrahydrofuran were then added dropwise at such a rate that gentle boiling occurred. When this addition was completed, the reaction mixture was stirred for 0.5 hour. Lithium complexes were decomposed by the addition of saturated ammonium chloride solution and phase separation occurred. The organic layer was diluted with 200 ml. of diethyl ether and then extracted twice with a total of 200 ml. of 2N hydrochloric acid. The acid extract was washed with 100 ml. of diethyl ether, basified with ammonia solution and the liberated basic products were extracted twice into a total of 120 ml. of chloroform. Concentration of the dried extracts produced a syrup which was applied to a 30 × 4 cm column of silica gel and eluted with a 4:1 mixture of chloroform/ethyl acetate. Twenty-four successive fractions of 25 ml. each were collected and examined by thin layer chromatography. Three main components were detected in the reaction mixture. The slowest moving compound had an identical mobility to that of the starting material. Fractions 1 to 13 were discarded since no product was detected. Fractions after 24 were discarded because they contained increasing amounts of starting material. Fractions 14 to 16 and 17 and 18 gave crystalline material upon trituration with ethanol and had identical infrared spectra. (No carbonyl functions were present). Recrystallation of this material from ethanol yielded 2-(3,4-dimethoxyphenyl)-2-(6-dibenzylmethyl-2-pyridyl)-1,3-dioxane, m.p. 124°C. Analysis: Calculated for C32H33NO4 : C, 77.55; H, 6.7; N, 218. Found: C, 77.65; H, 6.8; N, 3.0.

1. additionThis rate of addition
2. temperatureto maintain
3. customthe reaction at a gentle reflux
4. additionAfter the addition
5. additionfollowed by the addition of 18.9 g
6. additionWhen this addition
7. stirringthe reaction mixture was stirred for 0.5 hour
8. additionThe organic layer was diluted with 200 ml
9. extractionof diethyl ether and then extracted twice with a total of 200 ml
10. extractionThe acid extract
11. washwas washed with 100 ml
12. extractionthe liberated basic products were extracted twice into a total of 120 ml
13. customConcentration of the dried extracts produced a syrup which
14. washeluted with a 4:1 mixture of chloroform/ethyl acetate
15. customeach were collected
16. temperaturecontained increasing amounts of starting material
17. customFractions 14 to 16 and 17 and 18 gave crystalline material upon trituration with ethanol