Loading patent…
AssigneeSumitomo Chemical Company, Limited
InventorsMichihiro Yamamoto, Shigenari Katayama, Masao Koshiba, Hisao Yamamoto
Estimating the term…
3,4-Dihydro-2(1H)-quinazolinone derivatives of the formula, ##STR1## wherein R.sub.1 and R.sub.2 are each hydrogen, lower alkyl, lower alkylthio or lower alkoxy, or, when taken together, R.sub.1 and R.sub.2 may form methylenedioxy; R.sub.3 is polyhalo-lower alkyl; R.sub.4 is phenyl, halophenyl, lower alkoxyphenyl, lower alkylphenyl or thienyl; and X is oxygen or sulfur, which are known to be very useful intermediates for the preparation of anti-inflammatory and analgesic agents, are obtained in a high yield by reacting a compound of the formula, ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and X are as defined above, with a compound of the formula, R.sub.4 --CHO wherein R.sub.4 is as defined above, with heating in the presence of a zinc halide as a catalyst.
A process for preparing a 3,4-dihydro-2(1H)-quinazolinone derivative of the formula, ##STR6## wherein R.sub.1 and R.sub.2 are each independently hydrogen, lower alkyl, lower alkylthio or lower alkoxy, or, when taken together, R.sub.1 and R.sub.2 may form methylenedioxy;
Dependencies are inferred from the claim text.