3 ,4 - propanol derivative

Halogenated 2-propanol derivatives, eg, l,3-dichloro-2-propanol [96-23-1], are generally prepared from glycerol [56-81-5] (qv). These materials are used in the preparation of halogen-containing phosphates to plasticize and lower the flammability of plastics, eg, polyurethanes and ceUulosics. 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

Extension of the head group by insertion of a methylene group is tolerated, the A-propanol derivative (241) having a slight increase in binding affinity compared to AEA. Further extension of the carbon chain, such as the butyl derivative (242), led to a decrease in activity [150, 151]. 

Esterification of certain aromatic acids with p-aminoethanol and propanol derivatives frequently results in molecules that show local anesthetic... 

Excellent asymmetric hydrogenation of amino ketones has been applied for the syntheses of many chiral drugs. For example, the enantioselective hydrogenation of 3-aryloxy-2-oxo-l-propylamine derivatives can directly afford the l-amino-3-aryloxy-2-propanol derivatives as chiral / -adrenergic blocking agents. This has been successfully accomplished with a neutral MCCPM-Rh complex as the catalyst. With 0.01 mol.% of an (A,A)-MCCPM-Rh complex,... 

Higher differences for the interaction of both the biological and the synthetic receptors with the two enantiomers are found for the propanol-derivatives than for the ethanol-derivatives (Norephedrine, Metaraminol vs. Octopamime, Noradenaline Pseudoephedrine, Ephe-drine vs. Synephrine, Adrenaline). 

The radiosynthesis starts with the nucleophilic F-fluorination of 2-benzyloxy-4-formyl-A/,A/,A/-trimethylanilinium trifluoromethanesulfonate or 5-benzyloxy-2-nitrobenzaldehyde. Subsequent condensation with nitroethane yielded the corresponding 2-nitro-1-propanol derivatives. Reduction of the nitro moiety and deprotection provided the four stereoisomers of " F-labeled 2-amino-1-(4-fluoro-3-hydroxyphenyl)-1-propanol and 2-amino-1-(2-fluoro-5-hydroxyphe-nyl)-1-propanol, respectively. 4-p F]FMR was isolated from the 2-amino-1-(4-fluoro-3-hydroxyphenyl)-1-propanol stereoisomer mixture via semipreparative HPLC and additional chiral HPLC for enantiomeric resolution. In a similar manner enantiomeric pure 6-p F]FMR was obtained. From a synthetic point of view, 4-p F]FMR appeared to be the more promising candidate for PET investigations due to higher radiochemical yields. The main advantage of the nucleophilic approach over the electrophilic methods is the obtained high specific radioactivity (56-106 GBq/pmol) that is desired for safe use in humans with tracer doses far beyond the pharmacological level [173]. 

If a diastereomeric mixture of (S,S)-2,5-dimethyl-3.4-hexanediol esters 2 and 3 reacts with methylmagnesium bromide, the result is kinetic resolution, as verified for R1 = Bn. The diastereomeric mixture was prepared from the racemic ethylene glycol a-chloro boronic ester via transesterification with chiral diol. The products isolated were (S,S)-2,5-dimethyl-3,4-hexanediol [(/ )-2-phcnyl-l-methylethyl]boronate, diastereomeric ratio >95 5 as indicated by the rotation of the (/ )- -phenyl-2-propanol derived by deboronation with hydrogen peroxide, and (S,S)-2,5-dimethyl-3.4-hexanediol methylboronate. Phenylacetaldehyde was identified by 1H NMR4. 

The formation of 3-bromo-2-phenylchroman from the propanol derivative (246) is of interest because it forms part of the sequence utilized in the conversion of 4//-chromene into a 2//-chromene derivative (Scheme 62) (71S149). 

From the experiments in an initially acid medium it is apparent that the acid-catalyzed reaction is more rapid than the others and that secondary degradation into smaller units does not occur to any extent. The high yields of the propanol derivatives support the earlier conclusions that such units may indeed be joined through a 7-oxygen ether linkage. 

Adrenergic activities, of l-alkylamino-3-(2 thiazoloxy)-2-propanol derivatives, 410... 

In conjunction with a statin such as simvastatin, l,3-diaryl-2-pyridin-2-yl-3-(pyridin-2-ylamino)propanol derivatives, (IV), prepared by Kirsch (5) were effective as hypolipidemic agents in the treatment of arteriosclerosis. 

Analysis of the enantiomeric ratios of several p-blocking drugs (l-aryloxy-3-isopropylamino-2-propanol derivatives) is carried out by HPLC with UV or fluorescence detection after derivatization with (R)-NEI or (i )-(+)-l-(l-phenyl)ethyl isocyanate (in a reversed-phase system), or (S)-NEI (on silica gel) only the amine function of the drugs reacts with the NEI the hydroxy group does not. Similar schemes for HPLC determination of enantiomeric purity of tetrahydrofolate derivatives and of fluoxetine are also reported. 

The same reagent reacts with acyl chlorides to afford l,3-bis(trimethylsilyl)-2-propanol derivatives, which efficiently undergo a trimethylchlorosilane-prranoted Peterson reaction to afford allysilanes in high overall yields (equation 5). ... 

Norwicki, J., and J. Gora, Synthesis of New Fragrances fromFur-fural II. Synthesis of New 2-allq l-2-alkenyl-3-(2-furyl)propanol Derivatives, Pol. J. Chem., 65, 2267(1991). 

Alkaline (NaOH or KOH) treatment of W-methoxyisoxazolidines causes loss of methanol to give 2-isoxazolines.113 Howevever, in most cases N—O cleavage is brought about to give propanol derivatives. Sometimes further fragmentation takes place.118... 

Extraction of filters, fractionation onSPClS, BE3/ methanol or BE3/propanol deriv. 

In contrast to dialkylphosphines, which are more difficult to prepare, the reaction of amino alcohols with chlorodialkylphosphines does not provide any problems. Thus, compounds such as Cps-ProNOP 65 are obtained directly from chlorodicyclopentylphosphine and prolinol67 amino alcohols not derived from amino acids have also been successfully used, e.g., (S)-l-(methylamino)-2-propanol [derived from (S)-methyl lactate by aminolysis with methylamine and reduction with lithium aluminum hydride69], which led to Cy-isoAlaNOP 67 by reaction with chlorodicycl ohexylphosphine67. 

Reduction of the ester followed by tosylation furnishes the useful differentially protected propanol derivative 452 [141,142]. Removal of the THP group and subsequent cyclization gives (5)-( — )-methyloxirane (40) [141] (Scheme 64), the versatility of which has been discussed in sections 1.1 and 1.4.4. 

The same catalytic conditions were employed for the hydroformylation of isomeric vinylfurans (Scheme 4.64) [34]. With 2-vinylfuran as substrate, the relevant carbaldehyde was obtained with a maximum selectivity of 79% ee. (S)-2-Furan-2-yl-propanol derived upon subsequent hydrogenation is a potential precursor for the construction of biologically active compounds such as monensin (protein transport inhibitor) and the tumor-inhibiting compounds eriolanin, eriolangin, and ivangulin. Noteworthy, much better results were obtained in the hydroformylation of the isomeric 3-vinylfuran l/b = 92 8, 99% ee). 

---