of isatin (1b), malononitrile (2a), dimedone (3c) in the presence of (DABCO 30 mol%) at room temperature in H2O (5 ml) as a model reaction.
Also, most of the earlier processes suffer from lack of commonness for the synthesis of 4j from isatin, malononitrile and dimedone, but here we have observed the catalyst DABCO can be catalyzed formation of a wide range of spiro- pyran compounds.
2] and synthesis of 1,8-dioxooctahydroxanthene derivatives by condensation of dimedone and PPA-Si[O.
A mixture of an aromatic aldehyde (1 mmol), dimedone (2 mmol) and cerium(IV) ammonium nitrate (CAN) (10 mol%) in(20 mL) water was stirred at reflux temperature for 2-3 h.
Previous investigation of Glochidion multiloculare revealed glochidiol, glochilocudiol, glochidone and dimedone
14]C]methyltetrahydrofolate was purified just before use by treatment with dimedone
and extraction with toluene.
In the course of our study on the multicomponent reaction, we carried out the one-pot, three-component reaction of substituted benzaldehyde 1, dimedone 2 and malononitrile 3 in the presence of a catalytic amount of DABCO (10 mol%) in dioxan to give corresponding 4H-pyans 5 (Scheme-1).
In order to optimize the reaction conditions, some polar and non polar solvents such as methanol, ethanol, dimethyl sulfoxide, acetonitrile and chloroform were used in a model reaction of benzaldehyde 1, dimedone 2 and malononitrile 3 in the presence of catalytic amount of DABCO to investigate the effects of solvent for preparation of 4H-pyans 5.
A mixture of aldehyde 1 (1 mmol), dimedone 2 (1 mmol), ethyl acetoacetate 3 (1 mmol) and ammonium acetate (1 mmol) in PEG-400 (5ml) was stirred at 80[degrees]C in 25 mL round bottom flask for the appropriate time mentioned in Table 2.
In continuation of our research work on the development of novel synthetic methodologies , herein, we have reported a highly efficient route for the synthesis of polyhydroquinolines from one-pot four component coupling of an aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in PEG-400 (Scheme 1).
Catecholamines were measured by HPLC with fluorometric detection after extraction from plasma and derivatization with dimedone
Mixtures of benzaldehyde (12 mmol), dimedone
(10 mmol) and phthalhydrazide (10 mmol) were stirred in the presence of alum (10 mol %) in water (10 mL) for 5 min.