反应详情

To a solution of 2.77 g. (10 mmol.) of 3-acetyl-2,6-di-t-butylamino-4-methylpyridine (Compound V) in about 30 ml. of dry tetrahydrofuran stirred under nitrogen at 0° C., 6.2 ml. of a 1.6M solution of n-butyl lithium in hexane (10.3 mmol.) was slowly added so as to maintain the temperature below 5° C. 0.8 ml. of methyl iodide was then added and the reaction mixture was allowed to come to room temperature over a 1 hr. period. (Thin layer chromatography (25% ethyl acetate/hexane) revealed a mixture of two products (approximately 50% and 25%) and starting material (approximately 25%)). The reaction mixture was partitioned between chloroform and water, the aqueous phase was re-extracted twice with chloroform and the combined chloroform phases were dried over anhydrous sodium sulfate and evaporated at reduced pressure. Since the desired product in pure form could not be obtained from the residue by crystallization, the residue was dissolved in a minimum amount of chloroform applied to 250 ml. of silica (2.5 cm. column diameter) and eluted with 50% toluene/hexane. The fractions containing the desired (major) product were combined and stripped to dryness at reduced pressure and the residue was recrystallized from methanol/water to obtain the product as yellow crystals (1.3 g.), m.p. 102°-103° C.

1. temperatureto maintain the temperature below 5° C
2. additiona mixture of two products (approximately 50% and 25%)
3. customThe reaction mixture was partitioned between chloroform and water
4. extractionthe aqueous phase was re-extracted twice with chloroform
5. dry with materialthe combined chloroform phases were dried over anhydrous sodium sulfate
6. customevaporated at reduced pressure