thanks for the suggestions bees, but before dreaming of
obscure analogs, the alkylation must be made to work
two experiments with basically the same results were made. the difference was only
the longer reflux time of the second one.
i'll only describe the second one:
actone was stirred for 20h over anhydrous CuSO4 with the problems mentioned in
Post 336535
(hypo: "grey CuSO4 ", Chemistry Discourse).
about 25 ml of this acetone was distilled off and 1 g 5-iodo-vanillin (non recrystallised,
mp 175°C) was added under stirring. the 5IV dissolved nearly completely giving a reddish solution.
1 g anhydrous K2CO3 was added. after a short time a skin coloured (if you are caucasian)
precipitate formed. to this was added 1.7g EtI and the mixture was refluxed for 16 h. an
TLC was taken with inconclusive results, so another 0.8g EtI was added and the
reaction refluxed for another 24 h, when another TLC was taken with the same inconclusive
results. During the whole 40 h, the reaction did not change in appearance at all!
after cooling to room temperature, it was diluted with ether and the solids filtered off.
the solids were taken up in water, a tiny amount of gakk filtered off and the aqueous
solution acidified with 30% HCl. there was only very little precipitate (wich is probably
a good thing!). the ether/acetone was removed from the organic filtrate by distillation
and the residue (a yellow oil) taken up in a small amount of ether (it is very soluble
in ether!). this was then washed twice with Na2CO3 solution (to remove phenols and
carboxylic acids), dried over Na2SO4 and the ether removed by distillation. this
left a small amount of a yellow viscous oil, which gets hard in the freezer, but
does not crystallise.
i suppose that the oil does not crystallise, because there is still EtI in it.
how would you get rid of it, without sucking it into the oil pump??
if this turns out to be low yielding / total bunk, the only idea i have is
to use more solvent or another solvent (maybe there is solvation issues)
resp. more EtI...
official gene trash