تفاعل #8695

معادلة التفاعل

EA

K3PO4

1-bromo-2,4-dimethyl-benzene

→

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

المذيبات

THF

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONwas added under argon
2. 2
   درجة الحرارةThe mixture was refluxed for 96 h
3. 3
   ترشيحfiltered
4. 4
   أخرىThe filtrate was evaporated
5. 5
   أخرىthe 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)

الإجراء التجريبي

(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).

المصدر