反応 #8695

反応方程式

EA

K3PO4

1-bromo-2,4-dimethyl-benzene

→

2-(2,4-dimethyl-phenyl)-malonic acid dimethyl ester

溶媒

THF

反応条件

後処理

1. 1
   workup.ADDITIONwas added under argon
2. 2
   温度The mixture was refluxed for 96 h
3. 3
   ろ過filtered
4. 4
   その他The filtrate was evaporated
5. 5
   その他the resulting brown oil was purified on silica gel eluting with heptane:EA 4:1 to 1:1
6. 6
   workup.DISTILLATIONfollowed by distillation (bp 95–100° C. at 0.064 mbar)

実験手順

(In analogy to a procedure given in J. Am. Chem. Soc. 122 (2000), 1360–1370.) To a suspension of Pd(OAc)2 (758 mg), 2-(di-tert.-butlylphosphino)-biphenyl (2.02 g) and K3PO4 (65.95 g) in THF (350 ml) dimethylmalonate (21.42 g) and 1-bromo-2,4-dimethyl-benzene (25 g) was added under argon. The mixture was refluxed for 96 h, cooled to rt and diluted with EA (300 ml) and filtered. The filtrate was evaporated and the resulting brown oil was purified on silica gel eluting with heptane:EA 4:1 to 1:1 followed by distillation (bp 95–100° C. at 0.064 mbar) to give 2-(2,4-dimethyl-phenyl)-malonic acid dimethyl ester (5.66 g) as a colourless oil. 1H-NMR(300 MHz, CDCl3): 2.30(s, 6H), 3.75(s, 6H), 4.87(s, 1H), 6.98–7.05(m, 2H), 7.25–7.28(m, 1H).

出典