91049-48-8

Upstream product

• 623-96-1 Dipropyl carbonate 
• 321-98-2 (1S,2R)-(+)-ephedrine 
• 590-28-3 potassium cyanate 
• 101859-99-8 chlorodeoxypseudoephedrine hydrochloride 
• 98-85-1 1-Phenylethanol 
• 124-38-9 carbon dioxide 
• 126192-86-7 (-)-(1R,2R)-(N-t-butoxycarbonyl)pseudoephedrine 
• 75-44-5 phosgene 
• 90-82-4 rac-pseudoephedrine 
• 42510-95-2 N-((1RS,2RS)-2-hydroxy-1-methyl-2-phenyl-ethyl)-N-methyl-urea 
• 77-78-1 dimethyl sulfate 
• 7647-01-0 hydrogenchloride 
• 54418-69-8 4-methyl-5-phenyl-2-oxazolidinone 
• 74-88-4 methyl iodide 

Downstream Products

• 1201-56-5 (+/-)-N-methylephedrine 
• 90-81-3 ephedrine 

Relevant academic research and scientific papers

Synthesis of 2-Arylethylamines by the Curtius Rearrangement

2-Arylethylamine derivatives were synthesized using the Curtius reaction and with three different methods of preparing the acyl azide functional group. Carbamates derived from isocyanate were convenient protecting groups for alkylation of amines. Starting from benzaldehyde, amphetamine was prepared in three steps through an oxazolidin-2-one intermediate in 62% overall yield. Copyright Taylor & Francis Group, LLC.

Experimental and DEE study of the conversion of ephedrine derivatives into oxazolidinones. Double SN2 mechanism against SN1 mechanism

Sulfonation of the N-Boc derivatives of 1,2-aminoalcohols, such as ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, thiomicamine, and chloramphenicol yields a mixture of the corresponding oxazolidinones with inversion (erythro derivatives) and!or retention of configuration (threo derivatives)at C5. We suggest a competition between two mechanisms: an intramolecular SN2 process initiated by attack of the carbonyl oxygen of the Boc group to the benzylic carbon and the other one through a double SN2 process. In the erythro derivatives the first mechanism is predominant, while in the threo derivatives both mechanisms have similar energy. This hypothesis is supported by theoretical calculations and additional experimental assays.

Carbon dioxide as a carbonylating agent in the synthesis of 2-oxazolidinones, 2-oxazinones, and cyclic ureas: Scope and limitations

Carbon dioxide can be used as a convenient carbonylating agent in the synthesis of 2-oxazolidinones, 2-oxazinones, and cyclic ureas. The transient carbamate anion generated by treating a primary or secondary amine group in basic media can be activated with phosphorylating agents such as Diphenylphosphoryl azide (DPPA) and Diphenyl chlorophosphate (DPPCl) but also with other types of electrophiles such as SOCl2, TsCl, or AcCl. The intramolecular trapping of the activated carbamate by a hydroxyl group leads to the formation of 2-oxazolidinones or 2-oxazinones in good to excellent yields. This methodology was successfully applied to the synthesis of cyclic ureas up to 7-membered rings from the corresponding diamines.

Photocycloaddition of N-acyl enamines to aldehydes and its application to the synthesis of diastereomerically pure 1,2-amino alcohols

The regio- and stereoselective synthesis of the protected cis-3- aminooxetanes cis-5 and cis-7 is reported. The oxetanes were obtained by the photocycloaddition of aliphatic (6c-e) and aromatic (4, 6a) aldehydes to the corresponding enamides (1a-d,h) or enecarbamates (1e-g). The enamine derivatives used in the Paterno-Buchi reaction were either commercially available or prepared from the corresponding acetaldehyde imines 2 by acylation. The oxetane formation proceeded with good-to-excellent simple diastereoselectivity for aromatic aldehydes (56-82% yield) and moderate selectivity for aliphatic aldehydes (46-55% yield). The cis-3-aminooxetanes are precursors for syn- and anti-1,2-amino alcohols. The relative configuration established in the photochemical step was retained upon nucleophilic ring opening between the oxygen atom and carbon atom C-4. By this means, syn-1,2-amino alcohols such as 8 and 10 were available in good yields. In contrast, the N-Boc-protected cis-3-aminooxetanes cis-5e and cis- 5f were transformed into anti-1,2-amino alcohols. Upon treatment with trifluoroacetic acid, they underwent an intramolecular nucleophilic substitution at the carbon atom C-2 of the oxetane and the oxazolidinones 11 and 12 were formed. Because the substitution occurs with inversion of configuration, anti-1,2-amino alcohols, e.g., ephedrine (15), are accessible.

Kinetic resolution of secondary alcohols using proline-derived bicyclic iminium salts

The proline-derived bicyclic iminium salt 3 can be used to bring about kinetic resolution in its reaction with salts of secondary alcohols to give the corresponding methyl sulfides. Reaction proceeds most efficiently with sodium 1-phenylethoxide in toluene at RT where either 3 or the benzyl salt 14 give e.e.s of 21-25% and changing the heteroatoms present in the sails, the metal cation used and the solvent and temperature all give similar or lower selectivity.

Synthesis of optically active boroxazolidine, borathiazolidine and boraselenazolidine and their N-borane adducts from the corresponding 2- imino-heteroazolidines

The synthesis from the corresponding 2-imino-heteroazolidines of optically active boroxazolidine, borathiazolidine and boraselenazolidine, derived from ephedrine, and their N-borane adducts is reported. The X-ray diffraction structures of (4R,5R)-(+)-3,4-

STEREOSELECTIVE SYNTHESIS OF (+/-)-CONHYDRINE, (+/-)-EPHEDRINE, AND (+/-)-METHYLEPHEDRINE

(+/-)-Conhydrine, (+/-)-ephedrine, and (+/-)-N-methylephedrine have been synthesized with a complete stereochemical control by utilizing carbanions in which the negative charge is located at the position α to the nitrogen atom of N-acylamines.