40626-29-7

A method for the preparation of β-amino alcohol of formula (III) in which R1 is Ph, (substituted) Ph, R2 is C1-8 alkyl or C4-6 cyclo alkyl, R3 = R4R5CHNH2 where, R4 = H, C1-8 alkyl, C4-6 cyclo alkyl, or - COOR6 (R6=C1-C8 alkyl); R5 = (subst) aryl], the method including subjecting an α-hydroxy ketone of formula (I) in which R1 and R2 are as defined above is reacted with a chiral amine of formula R3NH2 where R3 = R4R5CH- where, R4 = H, C1-8 alkyl, C4-6 cycloalkyl, or - COOR6 (R6=C1-8 alkyl), R5 = (subst) aryl] to produce a compound of formula (II) in which R1, R2 and R3 are as defined above, followed by reduction to form the compound of formula (III).

In this article, a practically interesting route for the diastereoselective synthesis of phenylpropanolamines has been demonstrated for the first time. Using racemic O-tert-butyldiphenylsilyl (TBDPS) cyanohydrins as the starting materials, various syn phenylpropanolamines and derivatives (e.g., norpseudophedrine) have been successfully prepared in exellent diastereoselectivity via a practically interesting process.

(1R,2R)-1-Phenyl-1-alkyl/arylamino-2-(N-alkylamino)propane hydrochloride salts have been synthesized with high degree of enantiomeric purity from (1S,2R)-(+)-1-phenyl-2-(N-alkylamino)-1-propanol through the corresponding chloro derivatives. This reaction sequence involves three inversions with overall inversion of configuration at C-1. Copyright

An unusual class of chiral selectors, cyclofructans, is introduced for the first time as bonded chiral stationary phases. Compared to native cyclofructans (CFs), which have rather limited capabilities as chiral selectors, aliphatic-and aromatic-functionalized CF6s possess unique and very different enantiomeric selectivities. Indeed, they are shown to separate a very broad range of racemic compounds. In particular, aliphatic-derivatized CF6s with a low substitution degree baseline separate all tested chiral primary amines. It appears that partial derivatization on the CF6 molecule disrupts the molecular internal hydrogen bonding, thereby making the core of the molecule more accessible. In contrast, highly aromaticfunctionalized CF6 stationary phases lose most of the enantioselective capabilities toward primary amines, however they gain broad selectivity for most other types of analytes. This class of stationary phases also demonstrates high "loadability" and therefore has great potential for preparative separations. The variations in enantiomeric selectivity often can be correlated with distinct structural features of the selector. The separations occur predominantly in the presence of organic solvents.

A controlled release pharmaceutical preparation comprising a core containing a medicinal compound and a coating layer containing a water-repellent salt and a water-insoluble and slightly water-permeable acrylic polymer having trimethylammoniumethyl group. Said preparation releases a medicinal compound in a sigmoid type dissolution pattern irrespective of the PH of a dissolution medium.

The synthesis of both enantiomers of norephedrine and norisoephedrine is described to present a method for the preparation of enantiomerically pure branched 1,2-aminoalcohols.In a one pot reaction enantiomerically pure cyanohydrins bearing an acetal protective group are subjected to Grignard-reaction followed by addition of lithium aluminium hydride.After deprotection the target compounds are obtained.

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.