Diethyl malonyl dichloride

Malonic ester syntheses, 30, 7 Malononitrile, 37, 53 Malonyl dichloride, 33, 20 Mandelic acid, 36, 3 Mandelic acid, />-bromo, 35,11 Mannich reaction, with acetone, 37,18 Mercaptoacetaldehyde, diethyl ACETAL, 35, 51... 

Besides diethyl malonates, the active estersand malonyl dichlorides " have also been used as reaction partners of 2-aminopyridines. 

From malonic acid or diethyl (ethoxymethylene)malonate. Malonic acid 201 underwent nucleophilic acyl substitution with N-acetyl-3,4-dimethylphenylhydrazine 202 and phosphorus trichloride via in situ generated malonyl dichloride to afford pyrazoline-3,5-dione 203 which then underwent acid-catalyzed condensation with ethanol over molecular sieves to give 4-ethoxyrazol-3-one 204 (01JMC3730) (Scheme 45). 

Further labeled pyrimidines such as [2- C]barbituric acid (22, R, R = H) and its derivatives such as [2- C]barbital (22 R R = Et), and [2- C]pentobarbital (22 R = Et, R = 1-methylbutyl) are readily available from cyclocondensation of [ CJurea and the respective diethyl malonates in the presence of sodium ethoxide or butoxide. For phenobarbital (R = Et, R = Phe), decarboxylation of the malonate component was observed as a main side reaction, so that the respective malonyl dichloride had to be employed in order to achieve satisfactory yields. Analogous syntheses using unlabeled urea and labeled malonate derivatives are described in Chapter 6, Section 6.5. 

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