N-Acetylcysteine Amide Synthesis via Dithiothreitol Reduction
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Solution Overview
Problem
Current methods for synthesizing N-Acetyl Cysteine Amide (NACA) and its derivative, diNACA, face challenges in achieving high chemical yields and enantiomeric purity without the need for chromatography.
Innovation Solution
A process involving the reaction of cystine with an alcohol and a chlorinating reagent to form L-cystine dimethylester dihydrochloride, followed by conversion with triethylamine and acetic anhydride to form di-N-acetylcystine dimethylester, and subsequent reduction with ammonium hydroxide to produce NACA or diNACA, utilizing dithiothreitol as a reducing agent without metals, and further purification steps to achieve high yields and purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional synthesis methods are used, then NACA and diNACA can be produced, but the chemical yield and enantiomeric purity are insufficient and chromatography is required
Solution Approach 1:
The synthesis process is divided into distinct modular steps: (1) esterification of L-cystine with methanol to form L-cystine dimethyl ester, (2) acetylation with acetic anhydride to form di-N-acetylcystine dimethyl ester, (3) reduction with dithiothreitol to produce NACA or diNACA. Each step is optimized independently to maintain high enantiomeric purity while maximizing yield, eliminating the need for chromatographic separation.
Solution Approach 2:
The patent employs specific parameter optimizations including temperature control (reflux conditions for esterification and acetylation), stoichiometric ratios (excess methanol and acetic anhydride), and pH control during reduction with dithiothreitol. These parameter changes ensure high reaction efficiency and product purity without requiring chromatography, simultaneously improving both yield and enantiomeric purity.
2Ease of manufacture
If conventional synthesis methods are used, then NACA and diNACA can be produced, but the process complexity increases due to required chromatography
Solution Approach 1:
The patent extracts and eliminates the chromatography step from the synthesis process by optimizing the chemical reactions to produce high-purity products directly. The use of dithiothreitol as a reducing agent under controlled conditions produces NACA or diNACA with sufficient purity for pharmaceutical use without requiring complex chromatographic separation equipment, significantly simplifying the manufacturing process.
Solution Approach 2:
The patent replaces expensive and complex chromatography equipment with simple, inexpensive filtration and crystallization steps. The use of readily available reagents (methanol, acetic anhydride, dithiothreitol) and standard laboratory equipment (reflux apparatus, filters, centrifuges) makes the process accessible and economically viable without requiring sophisticated instrumentation.
3Productivity
If conventional synthesis methods are used, then NACA and diNACA can be produced, but the time consumption increases due to additional purification steps
Solution Approach 1:
The patent performs preliminary optimization of reaction conditions to ensure high product purity from the outset. By carefully controlling esterification, acetylation, and reduction conditions, and by selecting reagents that produce minimal side products, the synthesis process generates NACA or diNACA with sufficient purity directly, eliminating the need for time-consuming chromatographic purification steps and significantly reducing overall synthesis time.
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 effectively produces NACA and diNACA in high chemical yields and enantiomeric purity, eliminating the need for chromatography and optimizing the synthesis process.
Implementation Method 1
reducing dried di-N-acetylcystine dimethylester into N-acetylcysteine amide with dithiothreitol, triethylamine and an alcohol
Implementation Method 2
contacting cystine with an alcohol and a chlorinating reagent to form an organic solution containing L-cystine dimethylester dihydrochloride
Implementation Method 3
combining dried or undried L-cystine dimethylester dihydrochloride with a triethylamine, an acetic anhydride, and an acetonitrile to form a di-N-acetylcystine dimethylester
Data Source
AI summary
Presented herein are methods for making, isolating, and purifying N-acetylcysteine amide, (2R,2R′)-3,3′-disulfanediyl bis(2-acetamidopropanamide, diNACA), intermediates and derivatives thereof comprising: alternatively contacting cystine with methanol and a chlorinating reagent to form an organic solution containing L-cystine dimethylester dihydrochloride; combining dried or undried L-cystine dimethylester dihydrochloride with a triethylamine, an acetic anhydride, and an acetonitrile to form a di-N-acetylcystine dimethylester; mixing dried di-N-acetylcystine dimethylester with ammonium hydroxide to form a di-N-acetylcystine amide (diNACA); and separating dried di-N-acetylcystine dimethylester into N-acetylcysteine amide with dithiothreitol, triethylamine, and an alcohol.