3(2H)pyridazinone, process for its preparation and anti-allergic agent containing it.

摘要

A3(2H)pyridazinone of the formula:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="25" wi="85" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
wherein R<Sub>1</Sub> is hydrogen or C<Sub>1</Sub>-C<Sub>5</Sub> alkyl; R<Sub>2</Sub> is hydrogen, C<Sub>1</Sub>-C<Sub>8</Sub>-alkyl, chlorine or bromine; A is -NR<Sub>3</Sub>- or -0-; X is -(CH<Sub>2</Sub>)<Sub>n-</Sub>, -CH(OR<Sub>4</Sub>)-, -CO- or a single bond; when X is -(CH<Sub>2</Sub>)<Sub>n</Sub>- or a single bond, B is -O-, -S-, -NH-, -OS0<Sub>2</Sub>-, or -OCO- or a single bond, when X is -CH(OR<Sub>4</Sub>)-, B is -0-, -S-, -NH- or -OS0<Sub>2</Sub>-, and when X is -CO-, B is -O- or -S-; and each of Y<Sub>1</Sub>, Y<Sub>2</Sub> and Y<Sub>3</Sub> which may be the same or different, is hydrogen, C<Sub>1</Sub>-C<Sub>8</Sub> alkyl, C<Sub>2</Sub>-C<Sub>8</Sub> alkenyl, halogen, -OR<Sub>S</Sub>, -C0<Sub>2</Sub>R<Sub>6</Sub>, -CH=CHCO<Sub>2</Sub>R<Sub>7</Sub>, -CN,
<Chemistry id="chema02" num="0002"><Image id="ia02" he="19" wi="33" file="IMGA0002.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
-CON(R<Sub>8</Sub>)(R<Sub>9</Sub>), -COR<Sub>10</Sub>, or two of Y<Sub>1</Sub>, Y<Sub>2</Sub> and Y<Sub>3</Sub> togetherform
<Chemistry id="chema03" num="0003"><Image id="ia03" he="21" wi="36" file="IMGA0003.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
and a pharmaceutically acceptable salt thereof.