Propyl pyridine

Dcmgegeniiber bleibt die Konfiguration bei der Reduktion des optisch aktiven 2-(l-Hydroxy-l-phenyl-propyl)-pyridins zum 2-(l-Phenyl-propyl)-pyridin (-1,36 V 62% d.Th.) erhalten2. 

Inhibitors for proteases plasmepsin I and II of the malaria parasite Plasmodium falciparum, with a good plasmepsin/human protease cathepsin D selectivity, have been identified via library construction involving rapid microwave-accelerated Suzuki reactions [57]. The phenyl ring of the biphenyl unit in the lead compound M-((lS)-l- [((lS,2S)-3- [(lS)-2-amino-l-(4-phenyl-benzyl)-2-oxoethyl]amino -2-hydroxy-l-phenoxypropyl)amino]carbonyl -2-methylpropyl)pyridine-2-carboxamide has been altered by performing Suzuki reactions on N-((lS)-l- [((lS,2S)-3- [(lS)-2-amino-l-(4-bromobenzyl)-2-oxoethyl]amino -2-hydroxy-l-phenoxypropyl)amino]carbonyl -2-methyl-propyl)pyridine-2-carboxamide (Scheme 37). In particular, a 2-benzofuryl moiety proved to be interesting since a Ki value of 13 nM for plasmepsin I and... 

Musty or potato-like flavor and aroma have been observed as a defect in milk (Hammer and Babel 1957) and Gruyere de Comte cheese (Dumont et al. 1975). This off-flavor results from the production of nitrogenous cyclic compounds by Pseudomonas taetrolens and P. perolens (Morgan 1976). Musty-flavored compounds produced by these organisms include 2,5-dimethylpyrazine and 2-methoxy-3-isopropyl-pyrazine. The Gruyere de Comte with potato off-flavor contained 3-methoxy-2-propyl pyridine, as well as alkyl pyrazine compounds (Dumont et al. 1975). Murray and Whitfield (1975) postulated that alkyl pyrazines are formed in vegetables by condensation of amino acids such as valine, isoleucine, and leucine with a 2-carbon compound. Details of the synthetic mechanism in pseudomonads are unknown. 

The condensation products of amines and aldehydes have often been used as the reduc-tant. The most common commercial example is that arising from aniline and butyraldehyde for which the active ingredient has been identified as 3,5-diethyl-1,2-dihydro-l-phenyl-2-propyl-pyridine (DHP). A high purity grade, >85% active, has become available in recent years (Reilly Industries, PDHP Adhesive Accelerator Vanderbilt, Vanax 808 HP). 

Pyrolysis of poly(4-vinyl pyridine) was demonstrated to be a free radical process. Both poly(vinyl pyridines) generate as a main pyrolysis product the monomer, 2-ethenylpyridine or 4-ethenylpyridine, respectively. In the pyrogram of poly(2-vinyl pyridine), the dimer is also present (30% of the peak area). This peak is not seen in the pyrogram of poly(4-vinyl pyridine), but it is possible that the compound exists and elutes at a longer retention time than the one used in the chromatographic conditions applied for the pyrolysate separation. Other pyrolysate components not shown in Table 6.5.11 or 6.5.13 were reported in literature. Among these are propenylpyridine, isopropyl-pyridine, isoquinoline, phenylpyridine, 4,4 -dipyridyl, 4-[2-(4-pyridyl)ethyl]pyridine, 4-[2-(4-pyridyl)ethenyl]pyridine, 4-[3-(4-pyridyl)propyl]pyridine, etc. [39]. Similarly to the case of polystyrene, the H-T polymerization is prevalent in poly(vinylpyridine). However, some H-H units can be present in the polymer, and their abundance can be estimated from Py-GC/MS data. 

Cbz Cp DABCO DBU DDQ (DHQD)2CLB (DHQD)2PYR DMF DME DMPU DMSO Et Fmoc HMPA ia KHMDS LDA LiHMDS Me MEM Ms NaHMDS Ph Piv PMB Pr Py (saltmen)Mn(N) benzyloxy carbonyl p 5 -cyclopentadienyl l,4-diazabicyclo[2.2.2]octane l,8-diazabicyclo[5.4.0]undec-7-ene 2,3 -dichloro-5,6-dicyanobenzoquinone dihydroquinidinyl p-chlorobenzoale (see Chart 1) dihydroquinidinyl pyrimidine (see Chart 1) dimethylformamide dimethoxyethane l,3-dimethyl-3,4,5,6-tetrahydro-2(l//)-pyrimidinone dimethylsulfoxide ethyl 9-fluorenylmethoxy carbonyl hexamethylphosphoric triamide inverse addition potassium hexamethyldisilazide lithium diisopropylamide lithium hexamethyldisilazide methyl (2-methoxy ethoxy )methyl methanesulfonyl sodium hexamethyldisilazide phenyl pivaloyl p -methoxy benzyl propyl pyridine nitrido[A,A/-(l,l,2,2-tetramethyl) bis(salicylideneaminato)]manganese (see Chart 1)... 

Auf die gleiehe Wcise wird 2-(2-IIydroxy-athyl)-, 2-(3-Hydroxy-propyl)- und 2-Propyl-pyridin abgebaut. Durch Bestrahlung in Tetrahydrofuran wird 2-Methyl-pyridin gebildet1. In 3- oder 4-Stcllung entsprechend substituierte Pyridine bleiben unter diesen Reaktionsbedingungen unverandert. 

Ober Rhodium/Aluminiumoxid werden 3-Hydroxy-2-(dimethylamino-methyl)-pyri-din sowie 3-Hydroxy-2,6-bis-[dialkylamino-methyl]-pyridine in Salzsaure bei 307140 bzw. 160 bar mit sehr guten Ausbeuten zu den entsprechenden Piperidinen hydriert1 2. 3-Hydroxy-6-propyl-pyridin liefert mit Platin(IV)-oxid in Essigsaure (2073 bar) 96% d.Th. 3-Hydroxy-6-propyl-piperidin3. Analog werden 3-Hydroxy-l-alkyl-pyridinium-bromide iiber Raney-Nickel in Wasser (1507130 bar) hydriert4. 

Auf analoge Weise erhalt man aus l-Acetoxy-l-pyridyl-(4)-propan 4-Propyl-pyridin (90% d.Th. Kp10 73 -750)2. 

Die Reduktionen von 2-, 3- und 4-Acetyi- bzw. 2-, 3- und 4-Propanoyl-pyridinen mit amalgamiertem Zink in Salzsaure liefern die entsprechenden 1-Pyridyl-athanole bzw. propanole2. Bei 4-Propanoyl-pyridin wird zusatzlich 4-Propyl-pyridin (Verhaltnis 87 13) erhalten (vgl. auch S. 722). 

The size of the constituent in 2-position may have some bearing on hydrogenation in a neutral medium. A single instance involving the comparison of the reductions of 2-(2-hydroxyethyl) and 2-(3-hydroxy-propyl) pyridine (16) shows the latter compound being converted more rapidly to the corresponding piperidine. However, many more comparisons are necessary before this can become a valid conclusion. Smith (34) has stated that as the methyl group moves away from the... 

Oonyrin.—A basic substance produced by distilling coniln with zinc chlorid, is o propyl pyridin. / propyl pyridin is produced from nicotin by passing its vapor through a red-hot tube.. Two isomeric collidins, probably methyl ethyl pyridins, are formed by the action of fused KHO on cinchonin. 

Additional support for the yr-complex intermediate comes from the observation that j8-hydroxyisopropyl(pyridine)cobaloxime (35) rearranges to j8-hydroxy- -propyl(pyridine)cobaloxime (36) in the presence of acid (Fig. 45) (116). 

It should be pointed out that the only known example of pyridine containing branched substituent at C-2 [2-(l,l,l,3,3,3-hexafluoro-zi o-propyl)pyridine] was first prepared in 15% yield by reaction of pyridine oxide with (CF3)2C=CFC2p5 ° and later was synthesized through the reaction of (CF3)2C=S=0 and pyridine oxide in 70% yield. ... 

Figure 7.33 Two-step s3fnthesis of 2-(heptafluoro-i-propyl)pyridines.

As a final example, Golding and coworkers [92] obtained 2-acetoxyethyl- and 2-acetoxy- -propyl-(pyridine)cobaloxime by acylation of 2-hydroxyethyl- and 2-hy-droxy- -propyI-(pyridine)cobaloximes with acetic anhydride in pyridine. 

Dimethylamino)-l-(4-chlorophenyl)propyl]pyridine (chlortrimeton) 2-[N-Benzyl-N-(2-dimethylaminoethyl)amino]pyridine (pyribenzamine)... 

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