Hello, sorry for a late reply. Temperature have to be less than 65 *C. I fixed this mistake, I apologize.
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4′-Methylpropiophenone bromination to 2-bromo-4'-methylpropiophenone. Large scale.
Hello dear! If I use propiophenone and not 4-methylpropiophenone, do I need to change anything in this method? I hope to get bc-1 this way. And in the next step, from bq-1, through the method with ethyl acetate, acetone and hydrochloric acid, obtain an ephedron salt. Am I on the right track?
- By G.Patton
You have to recount reagent amounts according molecular weight of propiophenone.
Moles, grams, litres and chemical calculations
Moles, grams, litres and chemical calculations
Reaction temperature of 65 °C is simply wrong, since 2-bromo-4'-methylpropiophenone forms of crystals and lock 4′-methylpropiophenone inside. 2b-4m melting temperature is about 77 °C and it is very far from HBr boiling point. Consequently, 75-85 °C is a sweet range for your reaction temperature that should complete your halogenation roughly in 2 hours. The questions to answer:
1. will position of a bromine be right or you end with iso-mephedrone after amination?
2. will fraction of stereoisomers will be still 50:50 in this method?
1. will position of a bromine be right or you end with iso-mephedrone after amination?
2. will fraction of stereoisomers will be still 50:50 in this method?
- By w2x3f5
at elevated temperatures, side reactions are more likely, it is much better to carry out bromination in a solvent.
The question also arises about the decomposition of hydrogen peroxide at elevated temperatures, it is better to choose a replacement for this oxidizing agent.
so bromination without solvent and below the halogen ketone crystallization temperature is a very bad idea, there are complaints on the forum about the supplier of dirty halogen ketone in which there is a large admixture of the original ketone.
The question also arises about the decomposition of hydrogen peroxide at elevated temperatures, it is better to choose a replacement for this oxidizing agent.
so bromination without solvent and below the halogen ketone crystallization temperature is a very bad idea, there are complaints on the forum about the supplier of dirty halogen ketone in which there is a large admixture of the original ketone.
- By DavidNichols
I agree with you on using solvent for more even halogen distribution. H2O2 decomposition is unlike happen unless you reflux it up to 120-130 °C. The main issue is you having all the condition for di- and tri-halogenation. Stereo parity is also questioned, but its a pure speculation.
- By w2x3f5
Let's start with the fact that hydrogen peroxide self-decomposes over time during storage, naturally, the higher the temperature, the faster the decomposition, as well as local overheating when adding peroxide, where the temperature is much higher than the temperature of the reaction mass itself. Do not trust me, you can attach an empty bag to a reflux condenser and see how much oxygen is released from the decomposition of peroxide.
All conditions for polyhalogenation creates an excess of acid and the need to use peroxide in excess. I gave up peroxide a long time ago, it is the worst oxidizing agent for this reaction.
All conditions for polyhalogenation creates an excess of acid and the need to use peroxide in excess. I gave up peroxide a long time ago, it is the worst oxidizing agent for this reaction.
Good afternoon, tell me if it is possible to replace 4-methyloprofenone with another reagent
2-(1-bromoethyl)-2-(4-methylphenyl)-1,3-dioxolan ?
2-(1-bromoethyl)-2-(4-methylphenyl)-1,3-dioxolan ?
I was sent 2-bromo-4-Methylpropiophenone instead of 4-Methylpropiophenone, would sodium hydroxide reflux eliminate the 2-bromo?
- By w2x3f5
you can immediately obtain the substance you need from alpha-bromo-4-methylpropiophenone, write the CAS number of the substance you received
