• 제목/요약/키워드: Pechmann condensation

검색결과 4건 처리시간 0.016초

무 용매 조건에서 potassium dihydrogen phosphate를 촉매로 사용하는 쿠마린의 마이크로파-유도 단일 용기 내 합성 (Microwave-induced one-pot Synthesis of Coumarins Using Potassium Dihydrogen Phosphate as a Catalyst Under Solvent-free Condition)

  • Niralwad, Kirti S.;Shingate, Bapurao B.;Shingare, Murlidhar S.
    • 대한화학회지
    • /
    • 제55권3호
    • /
    • pp.486-489
    • /
    • 2011
  • Potassium dihydrogen phosphate는 마이크로파 조사조건에서 용매 없이 페놀과 아세토아세트산 에틸의 Pechmann 축합반응에 의하여 쿠마린을 합성하는 효과적인 촉매로 밝혀졌다. 이 방법은 쿠마린 합성에 있어서 소량의 촉매를 필요로 하며 수율이 높고, 반응이 깨끗할 뿐만 아니라 반응 시간이 짧은 장점들을 가지고 있다.

Ammonium Metavanadate: A Mild and Efficient Catalyst for the Synthesis of Coumarins

  • Mandhane, Priyanka G.;Joshi, Ratnadeep S.;Ghawalkar, Anant R.;Jadhav, Ganesh R.;Gill, Charansingh H.
    • Bulletin of the Korean Chemical Society
    • /
    • 제30권12호
    • /
    • pp.2969-2972
    • /
    • 2009
  • A mild and efficient method has been developed for condensation of substituted phenol with ${\beta}$-ketoester in the presence of catalytic amount of ammonium metavanadate (10 mol%) at ambient temperature to afford the corresponding substituted 4-methyl-2H-chromen-2-one in high yields under mild conditions. Utilization of commercially available inexpensive catalyst makes this manipulation very interesting from an economic perspective.

Selective Synthesis of 3,4-Dihydrocoumarins and Chalcones from Substituted Aryl Cinnamic Esters

  • Jeon, Jae-Ho;Yang, Deok-Mo;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권1호
    • /
    • pp.65-70
    • /
    • 2011
  • Coumarins are ubiquitous in plant kingdom and have been used as antitumor, antifungals, anticoagulants, insecticides. Chalcones are also widespread in plant kingdom and have been known to possess diverse biological activities; antibacterial, antifungal, antitumor and anti-inflammatory, etc. As they are considered as important natural products, numerous synthetic approaches have been reported up to the present. We devise a new selective method of preparing dihydrocoumarins and chalcones from aryl cinnamates by the selection of reagents. Dihydrocoumarin derivatives were prepared selectively by using intramolecular cyclization catalyzed by p-toluene sulfonic acid. Also, chalcones were prepared by Fries-rearrangement catalyzed by $TiCl_4$. This method can be used for preparing various coumarin & chalcone compounds.