Scalable synthesis of dipyrromethanes
AssigneeNorth Carolina State University
InventorsJonathan S. Lindsey, Savithri Dhanalekshmi, Joydev K. Laha, Masahiko Taniguchi
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Abstract
A (preferably nonaqueous) method of making a dipyrromethane is described. The comprises the steps of: (a) providing a reaction system consisting essentially of an aldehyde or acetal, excess pyrrole and a catalyst; (b) reacting the aldehyde or acetal with the pyrrole in the reaction system to form the dipyrromethane therein; (c) quenching the reaction system by adding a base thereto (preferably without simultaneously or concurrently adding water and/or an organic solvent thereto); (d) separating the catalyst from the reaction system; and then (e) separating the pyrrole from the reaction system to produce the dipyrromethane as a residual
Claims24
A non-aqueous method of making a dipyrromethane, comprising the steps of:
- (a) providing a non-aqueous reaction system consisting essentially of (i) an aldehyde or acetal, (ii) excess pyrrole and (iii) a catalyst;
- (b) reacting said aldehyde or acetal with said pyrrole in said non-aqueous reaction system to form said dipyrromethane therein;
- (c) quenching said non-aqueous reaction system by adding a base thereto without adding an organic solvent thereto;
- (d) separating said catalyst from said non-aqueous reaction system, wherein said separating step is carried out by gravity or filtration;
- and then
- (e) separating said pyrrole from said non-aqueous reaction system to produce said dipyrromethane as a residual.
Dependencies are inferred from the claim text.