Never ever add I2 to a mixture of H2O+P+E ! This will ruin your yields.
Odd. This has not been my experience at all.
And another thing to note here is to do freebase rxns
Freebase reactions do seem to give some advantage. There was a debate in this forum over yields from freebase reactions as opposed to reactions done with the HCl form. For a long time, I was convinced that the freebase form was the reason for the generally better yields from freebase reactions. At one particular time one of the extraction techniques I employed was particularly successful at producing very very clean HCl form pseudo...after two recrystallizations in alcohol and acetone, I would have brad like spikes of pseudo to react... To my amazement, the best yields I obtained were from reactions of that pseudo HCl. Granted, the difference between my best HCl yeild and my best freebase yield was was less than a percentage point. The experience convinced me that HCl was not deleterious to the reaction...and that the higher yields I had experienced from the freebase form was in fact due to it being cleaner on the whole than the salt form. Every time I cleaned pseudo HCl until the recrystallization in alcohol made those spikes, I got the same results.
Then the mix should be gently refluxed in an oilbath at 160c for at LEAST 48 hours.
Experience in this area indicated to me that an in-flask temperature of 100c was sufficient, and it was unnecessary to exceed an in flask temperature of 120C. We may be discussing the same temperature, if you are using the temperature of the oil bath. I also found that forty eight hour reactions on the whole gave a superior product to 36 hour reactions, but the edge was very small. There is a large difference in quality between eight hours and twenty four; less between twenty four and thirty six; and even less between thirty six and forty eight.