Samvidbuho
Rising Star
Hi All,
I've started working on a series of solubility studies aimed at perfecting the art of crystallization. This part is based on a solubility study I did on fumaric acid, in solutions of water, acetone (undried and dried) and ethanol. I found that the solubility of fumaric acid in even anhydrous acetone is still fairly low, and I devised a new salting method which takes advantage of the fact that fumaric acid is over 2.5x more soluble in ethanol.
Using the solutions described here allowed for rapid recovery of salts (ie 2.3g fully dried within 2 hours), and increased yields (almost 8g of additional salts were recovered from old solutions using FASA alone). Towards the end I describe some of the tricomponent solutions I made which work by modifying the volume and surface area of the dispersed droplets, and the results are definitely worth looking into. I have some great pictures too that are unique and interesting.
I posted this both to provide information that I was previously unable to find anywhere myself before conducting these experiments, and in addition I hope this can provide insight into further refinement and development of the process of fumarate salt precipitation.
From the Table of Contents:
I. Introduction
II. Molecular Sieves
A. Using Sieves Properly
B. Issues of Contamination
III. Alternatives to F.A.S.A.
A. Breaking Away from FASA Completely
B. Is Water Actually Ok to Use for Making DMT Fumarate Salts?
IV. F.A.S.W.
A. Limitations to FASW in Practice: Generation of Persistent Suspensions
B. Dealing With Suspensions, Method 1: Salting Out with Inorganic Salts
C. Dealing With Suspensions, Method 2: Salting Out with F.A.S.E.
V. Solubility Study
A. Quantification of Saturation Levels: Results
VI. F.A.S.E.
A. Advantage 1: Increased Solubilization of Fumaric Acid
B. Advantage 2: Enhanced Reaction Rates --> Quick Salt Recovery Times
C. Advantage 3: Ease of Salt Collection
D. Advantage 4: Increased Yields
E. Interesting Note #1: DMT Fumarate Salts from FASE have Altered Crystal Habits and Morphologies
F. Interesting Note #2: Freebases Converted out of Alternative Solutions May Also Exhbit Altered Morphologies
G. Interesting Note #3: Not All of the Dried Salts Were Re-soluble in Water
VII. Optimization of Salting Process Through Enhanced F.A.S.E. Solutions
A. The Yin and Yang of FASE and FASW: Advanced Salting Control
B. Multisolvent Systems and Dispersivity: Theory of Operation
VIII. Conclusions
I hope this proves useful.
I've started working on a series of solubility studies aimed at perfecting the art of crystallization. This part is based on a solubility study I did on fumaric acid, in solutions of water, acetone (undried and dried) and ethanol. I found that the solubility of fumaric acid in even anhydrous acetone is still fairly low, and I devised a new salting method which takes advantage of the fact that fumaric acid is over 2.5x more soluble in ethanol.
Using the solutions described here allowed for rapid recovery of salts (ie 2.3g fully dried within 2 hours), and increased yields (almost 8g of additional salts were recovered from old solutions using FASA alone). Towards the end I describe some of the tricomponent solutions I made which work by modifying the volume and surface area of the dispersed droplets, and the results are definitely worth looking into. I have some great pictures too that are unique and interesting.
I posted this both to provide information that I was previously unable to find anywhere myself before conducting these experiments, and in addition I hope this can provide insight into further refinement and development of the process of fumarate salt precipitation.
From the Table of Contents:
I. Introduction
II. Molecular Sieves
A. Using Sieves Properly
B. Issues of Contamination
III. Alternatives to F.A.S.A.
A. Breaking Away from FASA Completely
B. Is Water Actually Ok to Use for Making DMT Fumarate Salts?
IV. F.A.S.W.
A. Limitations to FASW in Practice: Generation of Persistent Suspensions
B. Dealing With Suspensions, Method 1: Salting Out with Inorganic Salts
C. Dealing With Suspensions, Method 2: Salting Out with F.A.S.E.
V. Solubility Study
A. Quantification of Saturation Levels: Results
VI. F.A.S.E.
A. Advantage 1: Increased Solubilization of Fumaric Acid
B. Advantage 2: Enhanced Reaction Rates --> Quick Salt Recovery Times
C. Advantage 3: Ease of Salt Collection
D. Advantage 4: Increased Yields
E. Interesting Note #1: DMT Fumarate Salts from FASE have Altered Crystal Habits and Morphologies
F. Interesting Note #2: Freebases Converted out of Alternative Solutions May Also Exhbit Altered Morphologies
G. Interesting Note #3: Not All of the Dried Salts Were Re-soluble in Water
VII. Optimization of Salting Process Through Enhanced F.A.S.E. Solutions
A. The Yin and Yang of FASE and FASW: Advanced Salting Control
B. Multisolvent Systems and Dispersivity: Theory of Operation
VIII. Conclusions
I hope this proves useful.
