Methods and intermediates for the synthesis of porphyrins

A method of making a compound of Formula II:

• wherein:
• Ra and Rb are each independently loweralkyl;
• R1 is H, alkyl or aryl;
• R2, R3, R4, and R5 are each independently selected from the group consisting of H, halo, loweralkoxy, and loweralkylthio;
• and
• A is selected from the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkenyl, cycloalkylalkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, alkoxy, halo, mercapto, azido, cyano, hydroxyl, nitro, acyl, alkoxy, alkylthio, amino, alkylamino, arylalkylamino, disubstituted amino, acylamino, acyloxy, amide, sulfonamide, urea, alkoxylacylamino, aminoacyloxy, hydrophilic groups, surface attachment groups, cross-coupling groups and bioconjugatable groups;
• said method comprising:
• reacting a dipyrromethane of Formula IV:
• wherein A, R2, R3, R4 and R5 are as given above with an N,N-dialkylmethylammonium halide of Formula V:
• wherein Ra, Rb and R1 are as given above, and X is halo;
• in a polar or nonpolar aprotic solvent selected from the group consisting of methylene chloride, chloroform, tetrahydrofuran, nitromethane, toluene, acetonitrile, and mixtures thereof at a temperature of from room temperature to 100° C. to produce said compound of Formula II.