Реакция #8695

Уравнение реакции

EA

K3PO4

1-bromo-2,4-dimethyl-benzene

→

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

Растворители

THF

Условия реакции

Обработка

1. 1
   workup.ADDITIONwas added under argon
2. 2
   ТемператураThe mixture was refluxed for 96 h
3. 3
   Фильтрацияfiltered
4. 4
   ДругоеThe filtrate was evaporated
5. 5
   Другоеthe 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)

Методика

(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).

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