w about 10??? C. in air or under an inert atmosphere, such as argon or nitrogen; adding the resulting mixture in a dropwise manner at a rate of about 0.5 milliliter per minute to about 10 milliliters per minute, and in an embodiment about 1 milliliter per minute to a stirred organic solvent, which can be a mixture comprised of from about 1 volume part to about 10 volume parts and preferably about