See https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html)
As you already wrote: "Kornblum, et al, in J. Amer. Chem. Soc. 78, 1497, 1956 showed that alkali nitrites, especially sodium nitrite, can be used in the preparation of nitro compounds if DMF was used as the solvent. Thus, if DMF is available, the silver nitrite synthesis may be omitted. Use 1-iodoethane dissolved in DMF and add excess sodium nitrite in DMF with vigorous stirring at 0 C. Stir for 2.5 hours until reaction is complete. If 1-bromoethane is used, stir for 6 hours. Yields 60%."
So you obviously don't have to prepare any silver nitrite when you use DMF.
And quote from the nitroalkane synthesis document on Rhodium's site:
"dimethyl sulfoxide (DMSO) can be substituted for the dimethylformamide (DMF) as solvent. Ethylene glycol also works as solvent."
So it should be clear to the attentive reader that both DMF and DMSO as well as ethylene glycol allow for the use of sodium nitrite directly, without having to prepare and dry a solid silver salt beforehand!
Still I am not able to see how this is related to building a low-budget vacuum desiccator - as drying solids isn't needed in this synthesis, neither with DMF nor with DMSO. And if you'd researched the document properly, you would've dicovered this link (https://www.thevespiary.org/rhodium/Rhodium/chemistry/ethyl.bromide.html)
(https://www.thevespiary.org/rhodium/Rhodium/chemistry/ethyl.bromide.html) - quote:
"Moisture can be readily removed from liquids by adding a solid hygroscopic substance which does not act chemically upon the liquid. The common dehydrating agents are calcium chloride, potassium carbonate, sodium sulphate (anhydrous), quicklime, etc. Alkalis can not of course be used for dehydrating organic acids, nor can calcium chloride be employed in conjunction with alcohols or organic bases, with which it combines. In the present instance it can be used. A few small pieces of the granulated or fused calcium chloride are added to the liquid. The flask is corked and left to stand for some hours until the liquid becomes clear. It is then distilled. A thermometer is inserted into the neck of the flask with the bulb just below the side tube. The flask is attached to a condenser and heated gently on the water bath, so that the liquid distils at a moderate speed (2-3 drops a second). The temperature is noted and the portion boiling at 35-43°C collected in a separate flask. This consists of ethyl bromide which may contain a little ether."
This is the only drying process being necessary - and I really can't see any other drying step required for this preparation..
(except you insist on using the tedious AgNO2 preparation of course)
indole_amine
Alas, the NaNO2/DMSO/ethyl bromide route to nitroethane doesn't work too well. TFSE reveals that bees have had problems during the years.
Post 77924 (missing)
(Biscuit2: "Nitroethane - Polymerised disaster?? Help please!", Methods Discourse) An explanation is offered in this thread, obviously nitrite scavengers help.
Post 173510 (https://www.thevespiary.org/talk/index.php?topic=7726.msg17351000#msg17351000)
(Karl: "Re: Roads to Nitroethane", Chemistry Discourse)
Post 250792 (https://www.thevespiary.org/talk/index.php?topic=8981.msg25079200#msg25079200)
(SpicyBrown: "Problem encountered during Nitroethane synth.", Methods Discourse)
Post 502445 (https://www.thevespiary.org/talk/index.php?topic=9732.msg50244500#msg50244500)
(hest: "Nitroethane", Methods Discourse)
Post 502896 (https://www.thevespiary.org/talk/index.php?topic=9732.msg50289600#msg50289600)
(karel: "Nitroethane synthesis", Methods Discourse) The convenience of using AgNO2 despite it's price and light sensitivity is discussed in this thread.