#2. DBT


[3D .mol Image]

SYNTHESIS: To a well stirred solution of 10 g indole in 150 mL anhydrous Et2O there was added, dropwise over the course of 30 min, a solution of 11 g oxalyl chloride in 150 mL anhydrous Et2O. Stirring was continued for an additional 15 min during which time there was the separation of indol-3-ylglyoxyl chloride. This intermediate was removed by filtration as used directly in the following step. The above indol-3-ylglyoxyl chloride was added, portionwise, to 20 mL stirred anhydrous dibutylamine. There was then added an excess of 2N HCl, the mixture cooled, and the resulting solids removed by filtration. These were recrystallized from aqueous EtOH to give, after air drying, 19.7 g (77%) indol-3-yl N,N-dibutylglyoxylamide with a mp 131-132°C.

A solution of 19 g indol-3-yl N,N-dibutylglyoxylamide in 350 mL anhydrous dioxane was added, slowly, to 19 g LAH in 350 mL dioxane which was well stirred and held at reflux temperature under an inert atmosphere. After the addition was complete, refluxing was maintained for an additional 16 h, the reaction mixture cooled, and the excess hydride destroyed by the cautious addition of wet dioxane. The formed solids were removed by filtration, washed with hot dioxane, the filtrate and washings combined, dried over anhydrous MgSO4, and the solvent removed under vacuum. The residue was dissolved in anhydrous Et2O and saturated with anhydrous hydrogen chloride. The solids that formed were recrystallized from benzene/methanol to give 12.6 g (64%) of N,N-dibutyltryptamine hydrochloride (DBT) with a mp of 186-188 °C.

EXTENSIONS AND COMMENTARY : The earliest reports that mention any human responses to DBT suggested that with an i.m. injection of 1 mg/Kg there was less effect than with DMT or DET. This report was discussed in the commentary on DMT, and it was stated that the dihexyl- homologue (DHT) was without any activity at all. The monohexyl homologue (NHT, see below) has been described as being, "inactive in a few patients," but has not been systematically studied.

What kinds of homologues of DMT can exist out there on that tryptamine nitrogen? Methyls, ethyls, propyls, butyls? These are already part of this story, known as DMT, DET, DPT and DBT. The di-iso-butyl analogue of DBT may best be called DIBT and it comes from indo-3-yl-N,N-di-(i)-butylglyoxylamide and LAH in a manner parallel to the DBT procedure given above. The HCl salt has a mp of 202-204 °C. The pairs of alkyl groups can go on and on forever, but the activity seems to drop off as they get longer. How about a pair of 5-carbon chains? Diamyltryptamine? DAT? I certainly can't use the alternate name dipentyltryptamine, as that would be in conflict with DPT which has already established a prior claim for use with dipropyltryptamine. And there is still some possible ambiguity in that there is one mention in the literature that N,N-diallyltryptamine is active, but neither dosage nor route was mentioned. Maybe it should be DALT. For carbon chains that are 7-carbons long, there can only be DST for diseptyltryptamine. The synonymous diheptyltryptamine would require DHT, and this has already been usurped by the 6-carbon job, dihexyltryptamine.

And as to trying to name anything higher, such as the N,N-dioctyltryptamine, forget it. The code would have to be, following all this logic, DOT. That term, at least its use as a code for a psychedelic drug, is already assigned to ALEPH in the phenethylamine series. There it stood for DesOxyThio, the DOM analog with a sulfur atom put in the place of an oxygen atom at a critical substitution position. So that pretty much cools any efforts to get ever longer chains on that nitrogen atom. They simply cannot be named. After all, there are only 26 to the third power combinations of the letters of the alphabet, around 17,000 possible three letter codes. I remember a statistical challenge from many years ago, sort of an intellectual's party game. How many people would you need to invite to your party to guarantee that there would be a 50:50 chance that two of your guests had the same birthday. Not any specific day; just the same day. My gut instinct was to say maybe half as many people as there were days in the year. Something over a hundred? But the answer was more like 25 or so. So, how many drugs with three lettered codes would you have to create, to have a 50:50 chance of having two with the same code? I have totally lost the technique for making the calculations, but I'll bet it might be less than a thousand. This particular difficulty may well soon arise, as we are already into the hundreds. One final thought. The group one longer than the octyl (8) is the nonyl (9) chain. And if one could create a meaning for a tertiary nonyl group, it would produce TNT as an abbreviation, and nothing much would dare ever go wrong with it.

But the DNA-like triplet code has other complications. What happens when there is just one substituent group on the tryptamine nitrogen atom? Mono-this and mono-that. Monomethyltryptamine has occasionally been called MMT but that might be seen as standing for two methyl groups. In this one case the compound with two methyl groups, DMT, already has a well established identity. But, as was discussed under N-ethyltryptamine, it is safer to reserve the two letters of a three letter code in front of the "T" for the two alkyl groups, when they are different. N-methyltryptamine (monomethyltryptamine) then becomes NMT and dimethyltryptamine stays as DMT. N,N- as a prefix is assumed and is simply left out. MMT looks like methyl-methyl tryptamine (which is already called DMT). For consistency, abandon the modest literature convention and use NMT. And the potential conflict between S for secondary and S for septyl is easily resolved by simply not making compounds with any alkyl substituents that are longer than six carbons.

Let me make a table to help unravel the codes used for variously substituted tryptamines. First, there can be things that are never considered in alphabetizing, things that are locators of groups, and they always come first in any code. And, the numbers preceed the Greek letters, which preceed the atom symbols, all separated by commas. As examples:



Then comes the name of the compound itself containing, as a rule, either three of four letters. The first letter either tells the number of the groups present, or it can be the first of these groups. As to number:

N is for nitrogen to which a single group is attached - indicates mono-substitution
D is for di-substitution
T is for tri-substitution
As to group names:
aliphatic alkyl groups groups with hetero-atoms
M is for methyl
E is for ethyl
P is for propyl
IP is for isopropyl
B is for butyl
IB is for isobutyl
SB is for sec-butyl
TB is for tert-butyl
A is for amyl
AL is for allyl
H is for hexyl
HO is for hydroxy
MeO is for methoxy
MeS is for methylthio
MDO is for methylenedioxy

And the last letter defines the class:
T is for tryptamine
C is for carboline
S is for serotonin
In this way, a monster such as 5,a,N-TTBT becomes, quite obviously, a tryptamine with three tert-butyl groups attached, one at the 5-position, one at the alpha-carbon next to the amine, and one on the amine nitrogen atom itself.

A last comment. Remember that many drugs have code names all their own and none of the above lettering applies. Examples are such as LSD, AL-LAD, pyr-T and even T itself.

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