- Method for recovering trans - P-aminocyclohexanol by low-concentration waste liquid
-
The invention relates to the technical field of medical chemical raw material recycling, and particularly discloses a method for recovering trans -amino cyclohexanol from low-concentration waste liquid. The method comprises the following steps: adjusting the waste liquor to alkalinity, adding benzaldehyde and stirring, filtering and drying to obtain trans -4 - (benzylidene - amino) - cyclohexanol. The trans -4 - (benzylidene - amino) - cyclohexanol was added to a sulfuric acid solution, and after stirring, the liquid was left standing to obtain trans - p-aminocyclohexanol sulfate aqueous solution. After stirring and decoloring, the alkali content of the filtrate is adjusted to - and after the reaction is stirred, the oil layer is left to stand, and extraction, concentration and purification of the extractant are added to the oil layer to obtain trans 10 - 25% -amino cyclohexanol. To the method, waste liquid discharged in industrial synthesis of ambroxol hydrochloride and alkali waste liquid generated by trans -amino cyclohexanol can be produced, and trans -amino cyclohexanol can be recycled.
- -
-
Paragraph 0028-0042
(2021/09/21)
-
- Highly chemoselective aerobic oxidation of amino alcohols into amino carbonyl compounds
-
The direct oxidation of unprotected amino alcohols to their corresponding amino carbonyl compounds has often posed serious challenges in organic synthesis and has constrained chemists to adopting an indirect route, such as a protection/deprotection strategy, to attain their goal. Described herein is a highly chemoselective aerobic oxidation of unprotected amino alcohols to their amino carbonyl compounds in which 2-azaadamantane N-oxyl (AZADO)/copper catalysis is used. The catalytic system developed leads to the alcohol-selective oxidation of various unprotected amino alcohols, carrying a primary, secondary, or tertiary amino group, in good to high yield at ambient temperature with exposure to air, thus offering flexibility in the synthesis of nitrogen-containing compounds. Strong as an ox: The highly chemoselective aerobic oxidation of unprotected amino alcohols to their corresponding amino carbonyl compounds has been achieved by using 2-azaadamantane N-oxyl (AZADO)/copper catalysis. This catalytic system oxidizes not only alcohols with tertiary amino groups but also those with secondary and primary amines in good to high yield at ambient temperature in air. bpy=2,2-bipyridyl, DMAP=4-(N,N-dimethylamino)pyridine.
- Sasano, Yusuke,Nagasawa, Shota,Yamazaki, Mai,Shibuya, Masatoshi,Park, Jaiwook,Iwabuchi, Yoshiharu
-
supporting information
p. 3236 - 3240
(2014/04/03)
-
- Alumina supported synthesis of β-lactams using microwave
-
N(4-hydroxycyclohexyl)-3-mercapto/cyano-4-arylazetidine-2-one were synthesised from N-(4-hydroxycyclohexyl)-arylaldimine by reacting with ethyl α-mercapto/α-cyanoacetate on basic alumina under microwaves, wherein not only the reaction time has been brough
- Kidwai,Venkataramanan,Kohli
-
p. 989 - 1002
(2007/10/03)
-