Industrial preparation method of anti-asthma drug pranlukast intermediate
The invention discloses a preparation method of a pranlukast intermediate N-(2-cyano-4-oxo-4H-chromene-8-yl)-4-(4-butoxyphenyl)benzamide (short for formula I), specifically a method for preparing N-(2-cyano-4-oxo-4H-chromene-8-yl)-4-(4-butoxyphenyl)benzamide by carrying out a dewatering reaction on 4-oxo-8-[4-(4-butoxyphenyl)benzamide]-4H-chromene-2-formamide (short for formula II). The preparation method of the pranlukast intermediate represented by the formula I is high in yield, good in product color, high in product purity and beneficial to industrial production.
-
Paragraph 0015-0020; 0022; 0024
(2020/04/17)
PROCESS FOR THE PREPARATION OF NITRILE COMPOUNDS
A process for the preparation of a compound of formula (I) or a salt thereof wherein R is an amino, nitro or —NHCOR1 group, wherein R1 is C1-C6 alkyl or phenyl optionally substituted by a —O—(CH2)sub
-
Page/Page column 4
(2008/06/13)
A process for the preparation of nitrile compounds used as intermediates in the synthesis of cysteinyl leukotrienes antagonists
A process for the preparation of a compound of formula (I) or a salt thereof wherein R is an amino, nitro or -NHCOR1 group, wherein R1 is C1-C6 alkyl or phenyl optionally substituted by a -O-(CH2)su
-
Page/Page column 7
(2010/11/30)
PROCESS FOR PRODUCING NITRILE COMPOUND
Processes for the preparation of the nitrile compound of formula (1). According to the present invention, the compound of formula (I) can be prepared cheaply and simply, therefore, the present invention is excellent as the industrial mass production metho
-
Page 4
(2008/06/13)
PROCESS FOR PRODUCING CHROMONE COMPOUND
A process for producing a dicarboxylic acid compound represented by the formula (4): wherein R1 and R2 are the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or
-
Page 24, 25
(2008/06/13)
Process of producing 2-cyano-4-oxo-4H-benzopyran compounds
There is disclosed a process of producing a 2-cyano-4-oxo-4H-benzopyran compound of the general formula (2): STR1 wherein R1 and R2 are independently hydrogen, halogen, hydroxy, C1 -C5 alkyl, C1 -Csu
-
(2008/06/13)
More Articles about upstream products of 136450-11-8