Method of synthesis and novel compounds for pharmaceutical uses

A method for treating hemoglobin or blood in vivo or in vitro to modify the affinity of hemoglobin for oxygen, said method comprising causing an effective amount of a compound of the formula:

• ##STR20## wherein R.sub.4 is selected form the group consisting of hydrogen, halogen, straight and branched chain alkyl of from 1 to 6 carbon atoms, aryl, cycloalkyl of 3 to 7 carbon atoms;
• and alkoxy of 1 to 6 carbon atoms;
• R.sub.5 and R.sub.6 may be the same or different and are selected from the group consisting of hydrogen, halogen, straight or branched chain alkyl groups of 1 to 6 carbon atoms;
• aralkyl groups wherein the alkyl portion has from 1 to 6 carbon atoms, cycloalkyl of from 3 to 7 carbon atoms and aryl;
• R.sub.7 is hydrogen or a straight or branched chain alkyl group of 1 to 6 carbons;
• R.sub.8 is halogen;
• R.sub.9 is hydrogen or halogen with the proviso that R.sub.9 may only be hydrogen when R.sub.12 is halogen;
• R.sub.10 is hydrogen or halogen and R.sub.12 is hydrogen or halogen, and the pharmaceutically acceptable salts thereof to come in contact with hemoglobin.