Methyl tetra-O-acetyl-α-d-glucopyranuronate: crystal structure and influence on the crystallisation of the β anomer

Hayes, John A.; Eccles, Kevin S.; Lawrence, Simon E.; Moynihan, Humphrey A.

doi:10.1016/j.carres.2016.01.012

Cited by 3 publications

(5 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No α anomer 24 was detected in any of the recrystallized batches of β anomer 23 . Thorough washing of the directly obtained β anomer 23 with methanol was also found to remove completely the α anomer 24 ; i.e., impurity 24 can be removed by efficient washing …”

Section: Impurity Occurrence In Crystallizations In Process Chemistrymentioning

confidence: 97%

See 1 more Smart Citation

Impurity Occurrence and Removal in Crystalline Products from Process Reactions

Moynihan

Horgan

2017

Org. Process Res. Dev.

Self Cite

View full text Add to dashboard Cite

The behavior of impurities when subjected to crystallizations, and related processes such as recrystallization and reslurrying, has been reviewed with a particular focus on the years 2000−2015, but also including significant cases from outside that period. Small molecule pharmaceuticals and similar small organic molecules are included but not biomolecules, inorganics, or minerals. Phase impurities are only covered when a phase transformation is involved with the management of an impurity. Introductory examples illustrating some general features of crystallization as a method of purification are presented, as well as approaches to quantifying the effectiveness of purification. The review classifies cases based on the behavior of the specific impurities covered. The classes of behavior observed are the removal by washing, recrystallization, or reslurrying (Class I), impurities not being removed by these operations (Class II), and impurities which are removed in conjunction with a phase transformation (Class III). Examples of each of these types of behavior are presented, with many processes producing impurities which fall into more than one of these classes. Studies on the inclusion of extraneous molecules into crystalline materials are also covered. These particularly include the incorporation of compounds as solid solutions, but also eutectic formation and inclusion at surfaces during crystal growth. The relationship between types of impurities and behavior during processing is also examined.

show abstract

Section: Impurity Occurrence In Crystallizations In Process Chemistrymentioning

confidence: 97%

“…Thorough washing of the directly obtained β anomer 23 with methanol was also found to remove completely the α anomer 24; i.e., impurity 24 can be removed by efficient washing. 33 2.2. Class II Only.…”

Section: Impurity Occurrence In Crystallizations In Process Chemistrymentioning

confidence: 99%

Impurity Occurrence and Removal in Crystalline Products from Process Reactions

Moynihan

Horgan

2017

Org. Process Res. Dev.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This can result from residual mother liquor that has not been adequately washed away in the solid–liquid separation. Additionally, where impurities have a high affinity for the crystal surface, adsorption onto the crystal surface can reduce crystal purity. − The addition of a methanol wash after the filtration of β-methyl-tetra- O -acetyl- d -glucopyranuronate resulted in the removal of trace residues of the α-enantiomer present in unwashed crystals . In the crystallization of bisphenol A, a different problem solving approach was taken when the adhesion of mother liquor was found for the source of unwanted impurity molecules: Modification of crystallization conditions to increase overall particle size and remove small, fine particulates allowed for improved filtration of the product, resulting in an effective removal of the mother liquor and with it an increase in the purity of the crystals …”

Section: Impurities In Crystallizationmentioning

confidence: 99%

A Structured Approach To Cope with Impurities during Industrial Crystallization Development

Urwin

Levilain

Marziano

et al. 2020

Org. Process Res. Dev.

View full text Add to dashboard Cite

The perfect separation with optimal productivity, yield, and purity is very difficult to achieve. Despite its high selectivity, in crystallization unwanted impurities routinely contaminate a crystallization product. Awareness of the mechanism by which the impurity incorporates is key to understanding how to achieve crystals of higher purity. Here, we present a general workflow which can rapidly identify the mechanism of impurity incorporation responsible for poor impurity rejection during a crystallization. A series of four general experiments using standard laboratory instrumentation is required for successful discrimination between incorporation mechanisms. The workflow is demonstrated using four examples of active pharmaceutical ingredients contaminated with structurally related organic impurities. Application of this workflow allows a targeted problem-solving approach to the management of impurities during industrial crystallization development, while also decreasing resources expended on process development.

show abstract

“…, lactose anomers, 21 these isomers can modify crystal morphology and impede growth. 22 However, the rate of tautomeric inter-conversion is usually slower than for conformers but faster than for diastereomers. 16…”

mentioning

confidence: 99%

“…16,18 In the cases of diastereomers with a slow rate of inter-conversion, which involves high energy barriers and long lifetime (few h), e.g., lactose anomers, 21 these isomers can modify crystal morphology and impede growth. 22 However, the rate of tautomeric inter-conversion is usually slower than for conformers but faster than for diastereomers. 16 There are two approaches in which solute molecules (monomers) can be incorporated into the growth site on a crystal surface: direct incorporation and surface diffusion (Scheme 1a).…”

mentioning

confidence: 99%