assyl, tsjanga apoligies for the late reply. I cannot get access to the paper. its title is Tetrahedron Letters 51 (2010) 2724–2726. "Cost efficient synthesis of amides from oximes with indium or zinc catalysts".
In the paper theres a section with a modification, 15mol% zinc nitrate, 2 mol hydroxylamine, 2 mol sodium bicarbonate, 1L toluene, 1mol aldehyde. reflux 16 hours, then cool and filter to get good yields of the amide in 1 shot (80% is common).
It may -or not- be better to reduce the zinc load to 12% it could be even less. i dont recall for sure whether it was this specific reaction what benefited. id sub toluene for xylene too.
I tried toluene in the oxime>amide procedure using zinc nitrate and got orange goo. With xylene i got the amide.
Also using the general procedure in the oxime>amide using the catalyst load suggested by the paper the amide was a sandy colour. reducing the catalyst load a few % helped and white amide was obtained but it may have extended reaction time by an hour or so.
My results take with a pinch of salt, theyre from memory not notes and id hate to mislead anyone. The procedure and mods was suggested by someone else who preferred the one step aldehyde>amide.
I personally preferred the two step and went back to it for i could get 105% to the oxime mp @54c and 70-75% in the beckman to the amide, mp @115-118c without any bother or effort. I figured by the time i was consistantly maxing yields id never make up the amount lost from exploring and fine tuning the parameters. But thats just me, not the brightest spark.
Hopefully the reply was worth the wait, sorry about dangling a carrot on a stick.
EDITED to add a few replies to other questions.
The helionnal kept air free cool in the dark lasted a few years until used. Once opened i heard after several months the MP of the formed oxime was depressed slightly to usual, fresh heli as starting material.
The oxime and amide kept well over a year in the freezer until used without noticeable detioration
Honey for you my friend! Very very nice!