27489-62-9Relevant articles and documents
Method for recovering trans - P-aminocyclohexanol by low-concentration waste liquid
-
Paragraph 0044-0068, (2021/09/21)
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.
One-pot Synthesis of 4-Aminocyclohexanol Isomers by Combining a Keto Reductase and an Amine Transaminase
Sviatenko, Olha,Ríos-Lombardía, Nicolás,Morís, Francisco,González-Sabín, Javier,Venkata Manideep, Kollipara,Merdivan, Simon,Günther, Sebastian,Süss, Philipp,H?hne, Matthias
, p. 5794 - 5799 (2019/08/30)
The efficient multifunctionalization by one-pot or cascade catalytic systems has developed as an important research field, but is often challenging due to incompatibilities or cross-reactivities of the catalysts leading to side product formation. Herein we report the stereoselective preparation of cis- and trans-4-aminocyclohexanol from the potentially bio-based precursor 1,4-cyclohexanedione. We identified regio- and stereoselective enzymes catalyzing reduction and transamination of the diketone, which can be performed in a one-pot sequential or cascade mode. For this, we identified regioselective keto reductases for the selective mono reduction of the diketone to give 4-hydroxycyclohexanone. The system is modular and by choosing stereocomplementary amine transaminases, both cis- and trans-4-aminocyclohexanol were synthesized with good to excellent diastereomeric ratios. Furthermore, we identified an amine transaminase that produces cis-1,4-cyclohexanediamine with diastereomeric ratios >98 : 2. These examples highlight that the high selectivity of enzymes enable short and stereoselective cascade multifunctionalizations to generate high-value building blocks from renewable starting materials. Introduction.
The Rhodium Catalysed Direct Conversion of Phenols to Primary Cyclohexylamines
Tomkins, Patrick,Valgaeren, Carlot,Adriaensen, Koen,Cuypers, Thomas,Vos, Dirk E. De
, p. 3689 - 3693 (2018/07/31)
Cyclohexylamines are important intermediates in chemical industry, which are currently produced from petrochemical sources. Phenols, however, are an attractive sustainable feedstock. We here demonstrate the transformation of phenols with ammonia to primary cyclohexylamines. In contrast to previously reported chemistry which used palladium catalysts, we here show that rhodium is an excellent catalyst for the formation of primary cyclohexylamines. Different parameters were studied and it was shown that the reaction is applicable to a scope of phenolic compounds providing high selectivity.