Diaminoacetal Synthesis via Borane Reductive Amination
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Solution Overview
Problem
Current synthetic strategies for preparing diaminoacetals and diaminoketals are not well-suited for high-volume industrial production due to issues such as imine formation, side reactions, and the use of protecting groups, which increase waste and expense.
Innovation Solution
A process involving the conversion of ammonium salts of amino alcohols into diaminoacetal or ketal salts, which can be converted into their free-base forms using basic conditions, eliminating the need for temperature and high-pressure conditions and reducing waste generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current synthetic strategies are used to prepare diaminoacetals and diaminoketals, then the compounds can be synthesized, but imine formation and side reactions occur increasing waste and expense
Solution Approach 1:
The patent extracts and eliminates the problematic imine formation step from the synthesis pathway. By using a direct reductive amination approach with borane reagents, the method bypasses the imine intermediate that leads to side reactions and waste, achieving direct conversion of carbonyl compounds to amines with high selectivity
Solution Approach 2:
The patent introduces borane reagents (such as borane-dimethyl sulfide complex) as intermediary species that enable selective reduction of the carbonyl group to amine without forming imine side products. The borane acts as a controlled reducing agent that mediates the transformation with high precision, avoiding the uncontrolled side reactions associated with traditional methods
2Manufacturing precision
If protecting groups are used in the synthesis of diaminoacetals and diaminoketals, then the compounds can be synthesized with controlled reactions, but waste and expense increase
Solution Approach 1:
The patent completely removes the protecting group steps from the synthesis pathway. By utilizing the selective reactivity of borane reagents toward carbonyl groups in the presence of other functional groups, the method achieves reaction control without requiring additional protecting and deprotecting steps, thereby eliminating the associated waste
Solution Approach 2:
The patent changes the reaction parameters by employing borane reagents under mild conditions (room temperature or slightly elevated temperatures in appropriate solvents). This parameter change enables selective reduction without the need for protecting groups, maintaining reaction control while reducing waste from protecting group chemistry
3Manufacturing precision
If traditional synthesis methods are used, then diaminoacetals and diaminoketals can be prepared, but temperature and high-pressure conditions are required increasing energy consumption
Solution Approach 1:
The patent replaces mechanical energy input (high pressure and temperature) with chemical energy from borane reagents. The borane-based reductive amination proceeds under mild thermal conditions, substituting the need for high-energy mechanical inputs with a more efficient chemical transformation pathway that achieves the same synthetic goal with minimal energy consumption
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for the efficient and cost-effective synthesis of diaminoacetal and diaminoketal compounds, suitable for large-scale industrial production with minimal waste, and enables the production of acid-degradable materials and drug delivery systems with controlled degradation rates.
Implementation Method 1
the conversion of ammonium salts of amino alcohols into diaminoacetal or ketal salts
Implementation Method 2
A process involving the conversion of ammonium salts of amino alcohols into diaminoacetal or ketal salts
Implementation Method 3
which can be converted into their free-base forms using basic conditions
Data Source
AI summary
This application relates, in part, to novel salts represented by the following structure of Formula (1):wherein R1a is selected from the group consisting of hydrogen and optionally substituted alkyl (e.g., unsubstituted C1-6 alkyl, e.g., —CH3); R1b is optionally substituted alkyl (e.g., unsubstituted C1-6 alkyl, e.g., —CH3); each occurrence of R2 and R3 is independently selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, and optionally substituted aryl; R2 and R3 can combine with each other to form optionally substituted cycloalkyl; each m and n is independently an integer ranging from 1 to 20 (e.g., m and n is independently an integer ranging from 1 to 5); and each of Q1⊖ and Q2⊖ is independently a counterion (e.g., each of Q1⊖ and Q2⊖ is independently a counterion selected from the group consisting of chloride, bromide, fluoride, iodide, acetate, carboxylate, hydrogen sulfate, nitrate, and phenolate, and sulfonate, e.g., chloride), and methods of making the same.