US 2005/0038262 A1Published application

Scalable synthesis of dipyrromethanes

AssigneeNorth Carolina State University

InventorsJonathan Lindsey, Savithri Dhanalekshmi, Joydev 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

Dependent claims

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.

3 more elements

Dependencies are inferred from the claim text.