Tips to fix slow reactions in snb method

I'm wondering what could cause the scenario of a SnB reaction that started off fine, but then the reaction slows down suddenly and how to fix it.. If ice water bath is the answer what are the guidelines for making one?


  • be more specific. what makes u think it 'slows down,' are you talking about phase I or Phase 2 of operation? contrary to popular belief i don't believe there's any visual indication the phase 2 side of things, i.e. saturation, that can tell us when to stop the reaction or not. if you're not producing enough AN in the beginning then you probably are using a poor NP solvent, are burping too much AN gas out of the RV to let it dissolve the Li, or aren't producing enough AN to finish the strip off. temperature of solvent matters less the when u use the right ones, diethethyl ether is king, followed by hexane. naptha and others require hot temperatures to absorb AN and transfer its protons to the Li; ether is number one (but it absorbs water from the air on its own so isn't entirely safe. i've heard of people pulling off the first phase with the RV entirely in their freezer; this would work if your ratios were just right and you knew what you were doing. it's smart tostart off cold then work it til it's hot, then ice bath that shit. do this 4-8 times over 90 min and you're golden bronze, literally.

    ice water bath, not water bath. alsodon't forget that water belongs on the outside of the RV surface. it the number one source of accidental flame. be careful.
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