申请人:ROHM AND HAAS COMPANY
公开号:EP0025498A2
公开(公告)日:1981-03-25
A 1-aryl-1,4-dihydro-4-oxopyridazine carboxylic acid ester of the formula:
is prepared by an improved process which comprises reacting, in a liquid medium and in the substantial absence of water available to undergo reaction to form undesired by-product(s), an alcohol with a hydrazone in the presence of (a) a strong acid catalyst and (b) a desiccant which serves to remove water of reaction. The alcohol used is of the formula ROH and the hydrazone used is of the for-
In the above formulae:
R is (C1-C6)alkyl, (C1-C4)alkoxy(C1C4)alkyl, (C3-C8)-cycloalkyl, (C3-C8)cycloalkyl(C1-C4)alkyl, halo(C,-C6)-alkyl, benzyl or benzyl the ring of which is substituted with up to two of the same or different substituents selected from chloro, bromo, methyl, ethyl, methoxy, cyano, nitro and trifluoromethyl;
R1 and R2 are selected from hydrogen and (C1-C4)-alkyl;
X is selected from halo, trihalomethyl, nitro, (C1-C4)-alkyl, (C1-C4)alkoxy, (C1-C4)alkylthio, (C1-C4)alkylsulfinyl, (C1-C4)alkylsulfonyl, cyano and carboxy, the X substituents being the same or different when n is > 1, and n is 0 or an integer of from 1-3.
The esters of Formula I find use as plant growth regulators.
式中的 1-芳基-1,4-二氢-4-氧哒嗪羧酸酯:
一种 1-芳基-1,4-二氢-4-氧哒嗪羧酸酯是用一种改进的工艺制备的,该 工艺包括在液体介质中,在基本上没有水的情况下,在(a)一种强酸催化剂和(b)一 种用于除去反应水的干燥剂的存在下,使一种醇与一种腙发生反应生成不需要的副产物。所用的醇的化学式为 ROH,所用的腙的化学式为
在上式中
R 是(C1-C6)烷基、(C1-C4)烷氧基(C1C4)烷基、(C3-C8)-环烷基、(C3-C8)环烷基(C1-C4)烷基、卤代(C,-C6)-烷基、苄基或其环最多被两个相同或不同的取代基取代的苄基,这些取代基选自氯、溴、甲基、乙基、甲氧基、氰基、硝基和三氟甲基;
R1 和 R2 选自氢和 (C1-C4)- 烷基;
X 选自卤、三卤甲基、硝基、(C1-C4)-烷基、(C1-C4)烷氧基、(C1-C4)烷硫基、(C1-C4)烷基亚磺酰基、(C1-C4)烷基磺酰基、氰基和羧基,当 n > 1 时,X 取代基相同或不同,n 为 0 或 1-3 的整数。
式 I 的酯类可用作植物生长调节剂。