Ketals and Polyketals as Release Agents
AssigneeThe Trustees of Columbia University in the City of New York
InventorsChathuranga C. DE SILVA, Porakrit LEOPHAIRATANA, Jeffrey T. KOBERSTEIN
Life of this patent
Estimating the term…
Abstract
Disclosed herein are ketal compounds, oligomers, and polyketals that are obtained in both high purity and high yield. These ketals and polyketals are utilized for their ability to readily release small chemical molecules, preferably fragrance molecules. Also disclosed are the utility of ketals and polyketals as delivery vehicles for controlled release of fragrances over time and/or on demand.
Claims25
A polyethylene glycol (PEG) linked ketal comprising a structure represented as:
- wherein R1, R2 are either the same or different derivatives of molecules/macromolecules with alcohol functionality(ies)
A synthesis process for producing a polyethylene glycol (PEG) linked ketal of Structure I
- comprising the steps of:
- (i) reacting a polyethylene glycol with a levulinic acid together with 1-ethyl, 3,(3-dimethylamino propyl) carbodiimide (EDC), 4-dimethyl amino pyridine (DMAP), and dichloromethane (DCM) to form a PEG linked ketal and
- (ii) reacting a fragrance molecule having one or more alcohol moieties with the PEG linked ketal in a presence of tetrabutylammonium tribromide (TBAB) and trimethyl orthoformate
- wherein R1, R2 are either one or more of mono- or poly-alcohol derivatives.
A process for decomplexation of fragranced PEG linked ketal compounds and consequent release of one or more fragrance molecules having at least one alcohol moiety, via an acid hydrolysis process step, as shown below:
- in which process, the PEG linkaged ketal is subjected to an environment where the conditions are acidic, or wherein the PEG linkaged ketal is contacted with an acid, whereby the PEG linkaged ketal structure undergoes an acid catalysis which releases the one or more fragrance molecules having at least one alcohol moiety and, in some cases, also acetone as a by-product.
A process for decomplexation of PEG-ketal compounds and consequent release of one or more fragrance molecules having at least one alcohol moiety, via an acid hydrolysis process step, as shown below:
- in which process, the PEG linkaged ketal is subjected to an environment where the conditions are acidic, or wherein the PEG linkaged ketal is contacted with an acid, whereby the PEG linkaged ketal structure undergoes an acid catalysis which releases the one or more fragrance molecules having at least one alcohol moiety and, in some cases, also acetone as a by-product.
A polyketal according to the structure II:
- wherein
- R′ is a terminated independent hydrogen, or R′ is a C1-C10 alkyl, or C5-C10 cycloalkyl and wherein R′—OH is a C1-C10 alkyl alcohol or a C5-C10 cycloalkyl alcohol and R′ of R′—OH is not H that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more aryl groups or combinations thereof;
- Z is a C1-C10 alkyl, and/or a C5-C6 cycloalkyl including cyclohexane, that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more aryl groups such that O—Z—O is an ester group in that it is derived from an acid in which at least one —OH group is replaced by an —O-alkyl or —O-aryl group
- and where n is in a range between 1-200.
A process of producing fragrance functional polyketals of Structure II
- according to the reaction scheme illustrated:
- wherein a diol (B) is reacted with 2,2-dimethoxypropane (A), and a mono-alcohol fragrance (HO—R′) in p-toluene-sulfonic acid (C) to provide a polyketal of Structure II;
- wherein R′ is a terminated independent hydrogen, or R′ is a C1-C10 alkyl, or C5-C10 cycloalkyl and wherein R′—OH is a C1-C10 alkyl alcohol or a C5-C10 cycloalkyl alcohol and R′ of R′—OH is not H that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more phenyl groups;
- Z is a C1-C10 alkyl, and/or a C5-C6 cycloalkyl including cyclohexane, that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more aryl groups such that O—Z—O is an ester group in that it is derived from an acid in which at least one —OH group is replaced by an —O-alkyl or —O-aryl group
- and where n is in a range between 1-200.
A process of acid catalysis of a polyketal with an acid at a pH of below 7 according to the following reaction scheme;
- wherein R′ of said substituents are H, C1-C10 alkyl, and/or a C5-C10 cycloalkyl and wherein R′—OH is a C1-C10 alkyl alcohol or a C5-C10 cycloalkyl alcohol and R′ of R′—OH is not H that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more aryl groups;
- and wherein;
- Z of said substituents is a C1-C10 alkyl, and/or a C5-C6 cycloalkyl including cyclohexane, that is optionally substituted with an oxygen in the ring and/or further optionally substituted with one or more aryl groups such that O—Z—O is an ester group in that it is derived from an acid in which at least one —OH group is replaced by an —O-alkyl or —O-aryl group.
Dependencies are inferred from the claim text.