Well, the mess was dried with low heat and was all thrown into a beaker with conc Na2CO3 solution. A metallic grey precipitate was filtered off and dried.
The melting point from this, and the powder earlier isolated from the aq solution was taken, but both solids didn't melt at 250°C.
Probably unreacted tryptophan.(but if it is why didn't it dissolve into the basic solution?)
Well, yesterday i dreamed that i took 10 gr of L-tryptophan, added 75ml DMSO and 2ml acetone, and refluxed the resulting suspension for 4 hours. After cooling there was left a dark red solution to which was added 700 ml dH2O.
Yellow-orange crystals precipitated
, this was allowed to stand 30 min and they were vacuum-filtered off, washed with dH2O and spread open on filter paper to air-dry (then i woke up, so they are still drying, i couldn't weigh 'em yet)
A small bit of half-dry crystals were put in the oven pre-heated at 120°C and they melted immediately.
(if its completely dry i will dream the mp with a cappilary tube)
I don't think i will try the copper-chelate route again, seems like too much a mess to me.
e109