反応 #8694

反応方程式

K3PO4

1-bromo-3,4-dimethyl-benzene

EA

→

2-(3,4-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 16 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

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 (455 mg), 2-(di-tert.-butylphosphino)-biphenyl (1.21 g) and K3PO4 (39.6 g) in THF (200 ml) dimethylmalonate (12.85 g) and 1-bromo-3,4-dimethyl-benzene 15.0 g) was added under argon. The mixture was refluxed for 16 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 to give 2-(3,4-dimethyl-phenyl)-malonic acid dimethyl ester (16.2 g) as a colourless oil which slowly crystallises. 1H-NMR (300 MHz, CDCl3): 2.25(s, 3H), 2.26(s, 3H), 3.75(s, 6H), 4.59(s, 1H), 7.10–7.20(m, 3H).

出典