First Birch-Benkeser reduction went not just alright but is looking like its going to kick ass and chew bubblegum.
Question is, do I quench it now, being lazy and claim my hard-worked for yield, or do I wait a few hours for further admixture of substrate to reduce. I COULD discharge the reduction by adding water or acid, and work it up. OR I could go grab some more substrate and whack it in there. BUT I haven't recrystallized the spare substrate. I kept some back lest this reaction not succeed, afterall, first time, walk before one runs, no?
I'd sooner not spend the time to be honest. I added a few hundred mg more substrate (original wt. almost 8g) and will leave it an hour or so then quench, methinks. I'd sooner spend the time to properly recrystallize the substrate until it is not just white, but of glass-like seethrough clarity when a single crystal be viewed before a bright light source. And get cleaner end product. Although this is a fairly tolerant reaction from my reading. Now I want to get a dry ice or liquid nitrogen condenser so I can speed things up. And experiment with molten alkali metals or molten lithium-calcium alloy as well as bugger around and see what I can do with strontium adsorbed onto silica gels, same as for the Ca-Li alloy, or other alkali metals, absorbed onto silica gel and then strongly heated apparently they can be rendered air tolerant yet highly active Birch reductant reagents, apparently calcium on fine silica gel can get a birch done in five minutes flat and at much higher yield than using lithium, sodium or potassium and one simply packs a vigreaux and elutes through it like a chromatography column, or something close to a setup like that.
Like it in principle at any rate. This took me hours, interluded by a walk in the woods. Cleaning up a lake of diethylene diglycol, and the kitchen extractor fan almost choking on ammoniacal fumes. That did lead to a funny moment. Having to tell my old man to keep out of the kitchen.
Old man: 'how will I know when its safe to go back in'
me-oh YOU'LL KNOW alright...you'll know..
