- From the production of amphetamine phenylpropanolamine
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A process for making compound of formula Ifrom a phenylpropanolamine salt of formula IIwherein:R1 is hydrogen or a lower alkyl group;each R2 is independently a hydrogen, halogen, lower alkyl group, lower alkoxy groups, lower alkyl group substituted with 1 to 5 halogens, lower alkoxy groups substituted with 1 to 5 halogens, or both R2 together when on adjacent carbons constitute a -O(CH2)xO- where x is 1 to 4, thereby forming a ring structure fused with the phenyl group;R3 is a C1-C8-alkyl group, a C1-C12-aralkyl group, C1-C12-alkaryl group, or a phenyl group, each optionally substituted by 1 to 5 substituents selected from halogen, hydroxy, or C1-C6-alkyl; andHX is an equivalent of an organic or inorganic acid,the process comprising:(a) acylating the phenylpropanolamine salt of formula II with an acylating agent in a solvent at elevated temperature to make a reaction mixture containing an O-acylated phenylpropanolamine salt of formula III which can be isolated by the addition of a crystallization solvent, or optionally this mixture can be used in the next step; and(b) hydrogenating the O-acylated phenylpropanolamine salt to make the compound of formula I in the presence of a catalyst.
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Page/Page column 13-14
(2008/06/13)
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- STEREOCHEMICAL COURSE OF THE REACTION OF 2-HALOETHYL ISOTHIOCYANATES WITH NUCLEOPHILES. sTEREOSPECIFIC ROUTE TO 4,5-DISUBSTITUTED Δ2-THIAZOLINES AND THIAZOLIDINE-2-THIONES
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Diastereoisomeric 1-chloro-1-phenyl-2-isothiocyanatopropanes have been prepared.They reacted stereospecifically with CH3ONa, diethylamine, aniline and NaSH to give pure cis or trans-4,5-disubstituted Δ2-thiazolines and thiazolidine-2-thiones whose configuration was determined using the nuclear Overhauser effect.The preponderant conformation of diastereoisomeric 1-chloro-1-phenyl-2-isothiocyanatopropanes was estimated on the basis of coupling constants of vicinal protons.
- Kniezo, Ladislav,Kristian, Pavol,Budesinsky, Milos,Havrilova, Katarina
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p. 717 - 728
(2007/10/02)
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