Topic: Expanded Bromosafrole Writeup (Read 1686 times)
0.5:1 H2SO4 (actually, just a hair less than equimolar)
Treatment of carbonyl compds with methylamine hydrochloride, NEt3 and Ti(IV) isopropoxide, followed by in situ Na borohydride redn. and straightforward aq. work-up, affords clean products in good to excellent yields. An equimolar mixture of methylamine hydrochloride and triethylamine is used as the mathylamine equivalent. This alleviates the use of excess gaseous methylamine.A source of nucleophilic methylamine which avoids the inconvenience of gaseous methylamine is exactly what we want.
A mixture of methylamine hydrochloride and triethylamine has been employed as the source of nucleophilic methylamine. The method conveniently avoids the use of gaseous methylamine, however, the overall reaction was slow.
https://www.erowid.org/archive/rhodium/chemistry/redamin.titanium.html
The title compound was prepared using the method reported by Camilleri et al. [9] with the following modifications: to a suspension of (±)-4 -methyl-2-bromopropiophenone (4.54 g, 20 mmol) and methylamine hydrochloride (1.35 g, 20 mmol) in dichloromethane (40 mL) was added triethylamine (5.58 mL, 40 mmol). The mixture was stirred at room temperature overnight and then acidified (pH ? 1) with 6 M hydrochloric acid (50 mL). The aqueous layer was washed with dichloromethane (3 × 50 mL), basified (pH ? 10) with 5 M sodium hydroxide (circa. 100 mL) and then re-extracted with dichloromethane (3 × 50 mL). The combined organic fractions were dried (MgSO4 ) and concentrated in vacuo to give a viscous yellow oil. The oil was dissolved in isopropanol (4 mL), treated with hydrochloric acid (3 M solution in butanol, 10 mL) and stirred at room temperature for 1 h. The mixture was diluted with diethyl ether (150 mL) and stirred to reveal
a pale yellow solid (circa. 30 min). The crude product was filtered, washed with diethyl ether and recrystallised from acetone to give (±)-4 -methylmethcathinone hydrochloride (1.09 g, 51.2%
from 2) as a colourless powder.
Synthesis, full chemical characterisation and development of validated methods for the quantification of (+/-)-4 '-methylmethcathinone (mephedrone) : a new "legal high".
Santali, Eman Y. ; Cadogan, Anna-Karina ; Daeid, Niamh Nic ; Savage, Kathleen A. ; Sutcliffe, Oliver B..
Journal of Pharmaceutical and Biomedical Analysis, Vol. 56, No. 2, 10.09.2011, p. 246-255.
DOI: 10.1016/j.jpba.2011.05.022
Synthesis full chemical characterisation and development of validated methods for the quantification of mephedrone.pdf
(687.52 kB - downloaded 16 times.)
I am just curious. The lack of satisfactory writeups makes me reluctant to give it a try. I have very limited resources and only a little knowledge so who knows
Some more examples of substitution-elimination reactions in the chemical literature originally provided by another staff member of the Hive:
SN2.pdf
(87.95 kB - downloaded 22 times.)
In other words, I have not found examples where newbies like me end up getting what they want.It is because they usually dont when they need to be spoon fed
Anyway thanks for reply and info.
Bright star's writeup gives you a good idea of the level of effort it takes to achieve what you want.Totally agreed
Damned i just lost the full reply when automatically getting logged out!QuoteIn other words, I have not found examples where newbies like me end up getting what they want.It is because they usually dont when they need to be spoon fed
Anyway thanks for reply and info.
I have not said you do, but you have to become more than just a newbee to actually have success, that involves you could answer some questions after looking for them yourself, and this is the effort that it takes to achieve what you want.Bright star's writeup gives you a good idea of the level of effort it takes to achieve what you want.Totally agreed
I have read everything i could get my hands on, nobody to ask, no one to talk about, and useing actual organic chemistry books borrowed from the library, and rhodiums archive too to get a look into both sides of praticing chemistry.
It could have made me able to compare what is bullshit and what is not, to success when i dreamed for the very first unbelievable time after nearly a year of theory (but i like the theoretic part as well and you should too).
Eventually, when i had a two year enduring training as a chemisty laboratory assistant a few years ago I possibly was able to do everything for the pratical part at the start of it because i have learned and teached it myself, that made me to realise how far I really got into it.
Actually I think to have such a forum behind his back would have made it a lot harder to start successful
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Best practical Sn2 writeup I've seenthank you!
My only concern would be the KCl byproduct...Sorry methanol is absolut non-otc to get here but if concentrated ethanolic lye is used in a good ice-bath and slow addition this one is covered;D
hmmm i dont have the specific pka in mind, but i guess triethylamine is a weaker base than methylamine and will not work for this one...
And even if it would work (it DOES NOT!) you would end up getting a cloud of methylamine gas puffing in the air and a chunk of triethylammoniumchloride and this is undesirable
While triethylamine is commonly employed in organic synthesis as a base, and other applications, I would NOT consider it as a reagent to freebase methylamine.HCl
The cost, compared to NaOH or KOH and, the hazard (Explosive limits, exposure) isn't justified.
