Phenyl ethanol amines

The phenyl ethanol amine derivatives epinephrine (U and norepinephrine ( ) are intimately associated with the sympathetic nervous system. These two neurotransmitter hor-... 

The drugs in this class share the phenyl ethanol amine moiety and a catechol surrogate in which the 3-hydroxyl is replaced by some other function that contains relatively acidic protons. 

A phenyl ethanol amine in which the nitrogen is alkylated by a long chain alphatic group departs in activity from the prototypes. This agent, suloctidil (43) is described as a peripheral vasodilator endowed with platelet antiaggregatory activity. As with the more classical compounds, preparation proceeds through bromination of the substituted propiophen-one ( ) and displacement of halogen with octyl amine. Reduction, in this case by means of sodium borohydride affords suloctidil (43). ... 

With some important exceptions, drugs in this class are conceptually related to the phenyl ethanol amines by the interposition of an oxymethylene group between the aromatic ring and the benzyl alcohol. 

The phenoxypanolamine tipropidil (52) interestingly exhibits much the same biological activity as its phenyl ethanol amine parent suloctidil (53). 

A rather simple derivative of imidazoimidazoline has been described as an antidepressant agent. Preparation of this compound starts with the displacement of the nitramine grouping in imidazoline derivative by phenyl ethanol amine The product of this reaction is then treated with thio-nyl chloride. The probable chloro intermediate ( ) cyclizes under the reaction conditions to afford imafen (5. ... 

Chapter 2. Phenethyl and Phenoxypropanolamines 1. Phenyl ethanol amines References... 

A recent patent describes the synthesis and catalytic use of Al-containing TUD-1 materials. Some of the reactions demonstrated inclnde hydrogenation of mesitylene (Pt as active metal) and dehydration of 1-phenyl-ethanol to styrene. Several other conceptnal reactions were also described, amongst others the Diels-Alder reaction of crotonaldehyde and dicyclopentadiene and the amination of phenol with ammonia. 

A typical example that illustrates the method concerns the lipase- or esterase-catalyzed hydrolytic kinetic resolution of rac-1-phenyl ethyl acetate, derived from rac-1-phenyl ethanol (20). However, the acetate of any chiral alcohol or the acetamide of any chiral amine can be used. A 1 1 mixture of labeled and non-labeled compounds (S)- C-19 and (f )-19 is prepared, which simulates a racemate. It is used in the actual catalytic hydrolytic kinetic resolution, which affords a mixture of true enantiomers (5)-20 and (J )-20 as well as labeled and non-labeled acetic acid C-21 and 21, respectively, together with non-reacted starting esters 19. At 50% conversion (or at any other point of the kinetic resolution), the ratio of (5)- C-19 to (1 )-19 correlates with the enantiomeric purity of the non-reacted ester, and the ratio of C-21 to 21 reveals the relative amounts of (5)-20 and (J )-20 (98). 

Benzylalkohole, Diphenyl- und Triphenyl-methanol reagieren mit Phosphorsaure-tris-[di-methylamid] bei hohcn Temperaturen unter Bildung der entsprechenden N,N-Dimethyl-amine in mafiigen bis guten Ausbeuten1. Aus 1-Phenyl-ethanol jedoch entsteht unter den gleichen Bedingungen als Hauptprodukt Styrol. 

Figure 57 Some of the biocatalytic steps using lipase developed at BASF Lipase-catalyzed kinetic resolution of a) phenyl ethanol 18 using succinic anhydride, b) Secondary amine 120 using ethyl methoxyacetate as acyl...

Anandamide is rapidly hydrolysed enzymatically to arachidonic acid and ethanol-amine by a fatty acid amide hydrolase (FAAH) [50], The molecular characterization, cloning and expression of FAAH have been reported in a recent study [51]. FAAH can be blocked with either the general serine protease inhibitor phenyl methy(sulphonyl fluoride [38] or with the highly efficient methyl arachidonyl fluorophsphonate [52], The non-steroidal antiinflammatory ibuprofen in therapeutic doses, but not aspirin, sulindac or acetaminophen, also inhibits anandamide metabolism [53], This observation may have therapeutic implications. 

Fig. 7.10 LC-MS analysis of Acid Red 37 reduction to the correspondent aromatic amines, l- 3-amino-5-[(aminoxy)sulfonyl]phenyl ethanol and 7,8-diamino-3[(aminoxy)sulfonyl] naphthalene-l-ol, catalyzed by an azoreductase isolated from Acinetobacter radioresistens bacteria (Ramya et al. 2010). (a) LC chromatogram and (b) MS spectra of Acid Red solution before bioreduction (c) chromatogram and (d) MS spectra of Acid Red solution after 24 h of bioreduction...

Add 0 -5 ml. of phenyl isothiocyanate to the distillate and shake the mixture vigorously for 3-4 minutes. If no derivative separates, crystallisation may be induced by cooling the flask in ice and scratching the walls with a glass rod. Filter off the crude product, wash it with a little 50 per nent. ethanol, and recrystaUise from hot dilute alcohol. (See Table 111,123 for melting points of phenylthiourea derivatives of amines.)... 

Appllca.tlons. MCA is used for the resolution of many classes of chiral dmgs. Polar compounds such as amines, amides, imides, esters, and ketones can be resolved (34). A phenyl or a cycloalkyl group near the chiral center seems to improve chiral selectivity. Nonpolar racemates have also been resolved, but charged or dissociating compounds are not retained on MCA. Mobile phases used with MCA columns include ethanol and methanol. 

Hydrolysis of an enamine yields a carbonyl compound and a secondary amine. Only a few rate constants are mentioned in the literature. The rate of hydrolysis of l-(jS-styryl)piperidine and l-(l-hexenyl)piperidine have been determined in 95% ethanol at 20°C 13). The values for the first-order rate constants are 4 x 10 sec and approximately 10 sec , respectively. Apart from steric effects the difference in rate may be interpreted in terms of resonance stabilization by the phenyl group on the vinyl amine structure, thus lowering the nucleophilic reactivity of the /3-carbon atom of that enamine. 

The benzene was distilled from the extract and the residue of d-N-methyl-N-benzyl-)3-phenyl-isopropylamine was distilled at reduced pressure. The thus obtained free base, distilling at 127°C at a pressure of 0.2 mm of mercury and having an np of 1.5515, was dissolved in ethyl acetate and a molar equivalent of ethanolic hydrogen chloride was added thereto. Anhydrous ether was added to the mixture and d-N-methyl-N-benzyl-)3-phenylisopropyl-amine hydrochloride precipitated from the reaction mixture as an oil which was crystallized from ethyl acetate to give crystals melting at 129° to 130°C. 

A -Phenyl-3//-azepin-2-amine (3), obtained in 25% yield by heating 2-methoxy-3//-azepine with aniline at 120 C for four hours,81 in refluxing ethanolic sodium benzenethiolate undergoes displacement of aniline and forms 2-(phenylsulfanyl)-3//-azepine (4).116... 

The number of reactions that fit into this second class are manifold. Some typical examples are the amine-catalyzed reactions of 2,4-dinitrochlorobenzene with n-butylamine in chloroform (k"/k = 2.59 l.mole-1)23, with allylamine in chloroform (k"jk — 4.60 l.mole-1)24 and with allylamine in ethanol (k"fk =0.36 l.mole-1)25 and the amine-catalyzed reaction of p-nitrofluorobenzene with piperidine in polar solvents (k"/k < 3.2 l.mole-1)26. A typical example of a strongly catalyzed system is the reaction of 2,4-dinitrophenyl phenyl ether with piperidine in 60 % dioxan-40 % water27. 

The synthesis of cyclopropenone imines 3 has been accomplished by several methods. Thus aromatic amines, e.g. p-nitraniline, can be reacted either with diphenyl cyclopropenone in HCl/ethanol or with the ethoxy cation 75 forming the immonium cation 150, which is deprotonated by tertiary bases to the N-(p-nitro-phenyl)-imine /5/llsl ... 

---