Morpholine amine protection

Bromophenyl)-9-fluorenyl group (BrPhF), a novel group for safety-catch amine protection. BrPhF is relatively acid-stable and can be successfully activated by Pd-catalyzed cross-coupling reaction of the aryl bromide with morpholine, followed by cleavage under mild conditions using dichloroacetic acid and triethylsUane [S. Surprenant, W. D. LubeU, J. Org. Chem. 2006, 71, 84Sj. 

Another method for deallylation of ally esters is the transfer of the allyl group to reactive nucleophiles. Amines such as morpholine are used[415-417], Potassium salts of higher carboxylic acids are used as an accepter of the allyl group[418]. The method is applied to the protection and deprotection of the acid function in rather unstable /f-lactam 664[419,420]. 

Cyclohexylamine is miscible with water, with which it forms an azeotrope (55.8% H2O) at 96.4°C, making it especially suitable for low pressure steam systems in which it acts as a protective film-former in addition to being a neutralizing amine. Nearly two-thirds of 1989 U.S. production of 5000 —6000 t/yr cyclohexylamine serviced this appHcation (69). Carbon dioxide corrosion is inhibited by deposition of nonwettable film on metal (70). In high pressure systems CHA is chemically more stable than morpholine [110-91-8] (71). A primary amine, CHA does not directiy generate nitrosamine upon nitrite exposure as does morpholine. CHA is used for corrosion inhibitor radiator alcohol solutions, also in paper- and metal-coating industries for moisture and oxidation protection. 

Various amines find application for pH control. The most commonly used are ammonia, morpholine, cyclohexylamine, and, more recently AMP (2-amino-2-methyl-l-propanol). The amount of each needed to produce a given pH depends upon the basicity constant, and values of this are given in Table 17.4. The volatility also influences their utility and their selection for any particular application. Like other substances, amines tend towards equilibrium concentrations in each phase of the steam/water mixture, the equilibrium being temperature dependent. Values of the distribution coefficient, Kp, are also given in Table 17.4. These factors need to be taken into account when estimating the pH attainable at any given point in a circuit so as to provide appropriate protection for each location. 

Succinimide is readily silylated by HMDS 2 to the N-silylated product 201, which seems, however, to be in equilibrium with the O-silylated derivative 202 a (cf the closely related reactive center in persilylated uridine 3) and reacts after 6-10 days at 24 °C with one equivalent of primary or secondary amines such as morpholine to give the crystalline colorless cyclic acylamidine 203 and HMDSO 7, even in the absence of any protective gas [33] (Scheme 4.12). The reaction is much faster on heating to 120 °C under argon. At these temperatures 201 and 202 a, and possibly also the acylamidine 203, are apparently partially O-silylated by HMDS 2 to the very sensitive 2,5-bis(trimethylsilyloxy)pyrrole 202b or to 2-tri-... 

Oils, greases and waxes are used for the temporary inhibition of corrrosion. They act as a barrier, preventing the condensation of water on the metal surface. Inhibitors such as piperidine (59) and morpholine (60) are often incorporated to give added protection. Volatile amines are also used in boilers they function by reducing the acidity of the steam condensate, thereby making it less corrosive. 

Benzodiazocine 264 was prepared through a 4-component Ugi reaction including a primary amine tethered to a BOC-protected internal amino nucleophile, followed by a postcondensation base-catalyzed cyclization. Thus, 2 equiv of aldehyde 262 were employed to promote Schiff base formation and a one-pot, double scavenging protocol with immobilized tosylhydrazine and di-isopropylethylamine removed both the excess aldehyde and any unreacted acid 261. The intermediate 263 was then subjected to treatment with TFA, followed by proton scavenging with resin bound morpholine, to promote cyclization to afford the eight-membered ring (Scheme 47) <2001TL4963>. 

Add DIPEA to the vessel (usually slight excess, 3.5-4 eq) and stir with a PTFE stick until complete dissolution of the A-protected amino acid occurs. Other tertiary amines can be used such as A-methyl morpholine or triethylamine. 

These were prepared to protect an aldehyde of an a-amino aldehyde and thus prevent racemization. A variety of amines were examined, and it was found that the morpholine derivative was the most stable and the ammonia derivative the least stable. The iminium ion could be regenerated upon treatment with ZnCL, but regen-... 

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