The isosafrole was added directly and undiluted to the performic.
Since isosafrole solubility in the performic is low you have to take your time, usually it took like 3 hours or so. The formyl glycol is completely soluble in the reaction mixture though. The temp was kept between 28-33°C to ensure a rapid enough reaction. Too much cooling will slow it down too much, and too much unreacted isosafrole, detectable by a thick oily layer on top will accumulate. When this happens, the isosafrole being added too fast, the temp will eventually rise, isosafrole solubility will go up, reaction rate also goes up, more isosafrole will react per given time and this might result in a runaway reaction especially when doing really big scale and unsupervised performics this way. Just take your time, drip it in slowly, stir it continuously, check the temp occasionally during the post-reaction stirring and nothing bad will happen.
Well, I sorta lied. Most of the time the addition funnel was swirled around with a little acetone after the addition to clean it a bit and get all the iso in, but that was a tiny amount compared to the original procedure.
When I did the performic for the first time in a 6L flask without acetone the internal temperature seemed to have stabilized around 28°C about 30 mins after addition with some external cooling and magnetic stirring.
Then suddenly I heard a scream outside, my ex being stung by a bee or wasp. Since she had taken some MDMA an hour before and showed an allergic reaction and was near faining I immediately drove her to the hospital, where she had to spend the night and the following day under surveillance in the intensive care unit due to her 'extreme physiological reaction' aka raised blood pressure, dilated pupils, fast heart beat, sweating, dry mouth etc.
She didn't really feel that bad (except for having to come down in an intensive care unit...), but the docs wanted to make sure she wouldn't die unexpectedly.
Talk about a botched attempt at tripping
.
Anyway, after about 2-3 hours, when I made sure she would live I came back to the lab, and the temp inside the flask had risen to 38°C! The post-addition reaction is definitely delayed when doing it without acetone! But the reason for this temperatre raise was rather the big flask size (meaning low surface area) and insufficient cooling, since the cooling water was piss warm (> 30°C) and all the ice I used had long ago melted. So I changed the cooling water, added some ice and no more surprises happened that day. Of course I went right back to the hospital
AFTER I made sure my precious batch would survive this incident. Yes bees, never forget where your priorities are. Sometimes the girlfriend has to step back and make way for more important stuff hehe.
Yield in that run was the usual 60%. Girlfriend survived without any permanent physiological damage. But she was a damn nutcase anyway...