1- Benzyl-2-morpholino

Quinoxalines with a cychc substituent other than an unsubstituted cycloalkyl, morpholino, phenyl, or piperidino group Quinoxalines bearing a substituent with more than six carbon atoms, except for an unsubstituted benzyl or benzoyl group Quinoxalines with two or more independent functional groups on a single substituent... 

Benzylidenehydrazino-2( 1 //)-quinoxalinone l-Benzyl-3-methylamino-2(l//)-quinoxalinone l-Benzyl-6-methyl-3-morpholino-2(l//)-... 

Azadienes of this sort were studied simultaneously by Mariano et al., who reacted mixtures of (1 ,3 ) and (1E, 3Z)-l-phenyl-2-aza-l,3-pentadiene 275 with several electron-rich alkenes, e.g., enamines and enol ethers (85JOC5678) (Scheme 61). They found the (l ,3 )-stereoisomer to be reactive in this process affording stereoselectively endo 276 or exo 277 piperidine cycloadducts in 5-39% yield, after reductive work-up with sodium borohydride. The stereochemistry of the resulting adducts is in agreement with an endo transition state in the case of dienophiles lacking a cis alkyl substituent at the /8-carbon (n-butyl vinyl ether, benzyl vinyl ether, and 1-morpholino cyclopentene), whereas an exo transition state was involved when dihydropyrane or c/s-propenyl benzyl ether were used. Finally, the authors reported that cyclohexene and dimethyl acetylenedi-carboxylate failed to react with these unactivated 2-azadienes. 

Figure 14.6 Resonance stabilization of reactive intermediates from (i) bis(chloromethyl) ether, (ii) aliphatic nitrogen mustard, (iii) allyl chloride, (iv) benzyl chloride, (v) bis(morpholino)methane, (vi) benzoyl chloride, and (vii) dimethylcarbamyl chloride.

N=PPh3, morpholino, cyclopropylamino (4-benzyl-2-morpholinyl)methylamino, 2-morpholinoethylamino R3 = H, Me, Ph R4 = H, Me... 

Intramolecular reaction with nucleophilic groups can also lead to heterocycles. For example, good yields of 3-acylbenzofurans result from cyclization caused by intramolecular substitution of the tertiary amino group by a phenol formed by cleavage of a phenol ether by boron tribromide251 (equation 182). 0-Hydroxy benzyl alcohols were used to obtain 4//-chromenes by their reaction with 4-morpholino-3-buten-2-one in acetic acid-acetic anhydride187. 

Vinylogous thioamides 33 (NR2 = dimethylamino or morpholino) react with benzyl chloride to give thiophenes42, while thienyl ketones are produced from a-bromo ketones43 (equation 22). 

Benzyl-piperazino)-6-cyano- - 914 3-Bromo-6-chloro-6-methyl- - 1459 3-Bromo-6-chloro-6-methyl- -4,5-dimethyl- 1459 6-Cyano-6-morpholino- - 908 6-Cyano-6-piperidino- - 908 - -4,5-diphenyl- 278 1-Ethinyl- -4,5-dimethyl- 1786 1-Formyl- -4,5-dimethyl- 1786 1-Hydroxymethyl- -4,5-dimethyl- 294... 

Anilino-4-(4-methyl-phenylsulfonyl)- 149 2-Anilino-5-nitro- 285 2-Anilino-5-(4-niti o-phenyl)- 171 aus S-(4-Nitro-benzyl)-N-phenyl-isothioharnstofl /Dimethoxy-morpholino-mcthan 168 2-Anilino-5-nitro-4-phenyl- 136 2-Anilino-4-phcnyl- 88... 

BenZoylamino-thiocarbonyl)-ethoxycarbonyl-methyll-4-hydroxy- 8 2-Benzoyl-3-benzyl-5-ethoxycarbonyl-4-methyl-2,3-dihydro- 356 5-Benzoyl-2,4-bis-[4-methoxy-phcnyl]-aus 4-Methoxy-N-(4-methoxy-a-morpholino-bcnzyliden)-thio-benzamid und -Brom-aceto-phcnon 135 5-Benzoyl-2-chlor- 263... 

Benzy 1-5-hydroxy- 638 5-Benzyl-l-(2-hydroxy-ethyl)-3-phenyl- 477 4-Benzyl-5-hydroxy-l-(morpholino-mcthyl)-3-phcnyl- 405... 

Benzyl-6,8-dimethyl-4-morpholino-5,6,7,8-tetrahydropyrido 4,3-[Pg.212]

Morpholino- and Amino-Ketones These classes of photoinitiators present a good activity [Is], The cleavage mechanisms ((10.16) and (10.17)) and the reactivity of the excited states have been fully reported [2i,30], Excellent representatives of morpholino ketones are 2-methyl- l-(4-methylthiobenzoyl)-2-morpholino-propan-1-one TMPK (10.16) and 2-methyl-l-(benzoyl)-2-morpholino-propan-l-one MPK. In amino ketones, the introduction of a morpholino moiety on a benzoyl group such as in 2-benzyl-2(diethylamino)-4,-morpholinobutyrophenone MPPK (10.17) red shifts the absorption. In both cases, efficient initiating radicals are generated. 

Isoflavones. - An interesting condensation of a benzyl cyanide with a salicylic ester (173) in boiling pjn-idine containing t-butoxide has given 2-aminoiso-flavones (174). Robustigenin (176), which occurs in Derris robusta, has been synthesized from the deoxybenzoin (175). An earlier report that iso-flavone may be synthesized via an enamine has been disputed and the procedure shown to yield 2-morpholino-2/f-isoflavene/ ... 

In an effort to follow modem trends toward green chemistry, a new odourless, water-soluble DMS equivalent (19) that is recyclable was introduced by the same group.5 Up to 89% of this new morpholino sulfide can be recovered using simple acid/base extraction techniques. Yields using this new DMS alternative are excellent and vary from 85% to 99% depending upon substrate, stoichiometry, and solvent choice. For example, the transformations illustrated above (12 to 14 and 15 to 17) were repeated using sulfide 19 and yields of 94% and 91%, respectively, were reported. In addition, the highly successful oxidation of benzylic alcohol 18 and allylic alcohol 21 were carried out at low temperatures. 

Enamines have enabled hydroxybenzofurans to be synthesised. 1,4-Benzoquinone in benzene treated with 2-(4-morpholino)-1-phenyl-1-propene at ambient temperature during 1 hour followed by hydrolysis of the intermediate with ethanolic hydrochloric acid gave 2-benzyl-5-hydroxybenzofuran in 46% yield, a compound relatively inaccessible by the standard intramolecular Claisen condensation (ref.73). 

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