Study of anthranilates cyclization to 2-hydroxymethyl-2,3-dihydroquinazolin-4(1H)-one derivatives and alternative way of their synthesis
摘要:
Applicability of the previously described rearrangement of 2-oxo-2-phenylethyl 2-amino-benzoate leading to 2-phenyl-2-hydroxymethyl-2,3-dihydroquinazolin-4(1H)-one has been studied. To test the limits of the reaction, various starting compounds such as 2-oxopropyl 2-aminobenzoate, 2-oxo-2-phenylethyl 2-aminobenzoate and 3,3-dimethyl-2-oxobutyl 2-aminobenzoate as well as some of their corresponding N-methyl and N-phenyl analogues were used. The structure-reactivity dependence was observed giving the expected products only in specific cases and in limited yields. Structure of the dihydroquinazolin-4(1H)-one skeleton was unambiguously confirmed with use of X-ray analysis of two selected compounds. Finally, an alternative way for the preparation of the desired derivatives was developed.
Applicability of the previously described rearrangement of 2-oxo-2-phenylethyl 2-amino-benzoate leading to 2-phenyl-2-hydroxymethyl-2,3-dihydroquinazolin-4(1H)-one has been studied. To test the limits of the reaction, various starting compounds such as 2-oxopropyl 2-aminobenzoate, 2-oxo-2-phenylethyl 2-aminobenzoate and 3,3-dimethyl-2-oxobutyl 2-aminobenzoate as well as some of their corresponding N-methyl and N-phenyl analogues were used. The structure-reactivity dependence was observed giving the expected products only in specific cases and in limited yields. Structure of the dihydroquinazolin-4(1H)-one skeleton was unambiguously confirmed with use of X-ray analysis of two selected compounds. Finally, an alternative way for the preparation of the desired derivatives was developed.
Preparation of 1,2-disubstituted-3-hydroxy-4(1<i>H</i>)-quinolinones and the influence of substitution on the course of cyclization
作者:Pavel Hradil、Jan Hlaváč、Karel Lemr
DOI:10.1002/jhet.5570360121
日期:1999.1
Synthesis of 1,2-disubstituted-3-hydroxy-4(1H)-quinolinones by the cyclization of N-substituted phenacyl or acetonyl anthranilates is described. Two methods were employed for cyclization of anthranilates. Heating in polyphosphoric acid has a wide scope of applicability. The thermal cyclization in boiling N-methylpyrrolidone is limited by steric effect.