3.4- Dihydro-6- pyrrolo pyrazine

Azomethine ylides of pyrrolo[l,2- ]pyrazine <1996JOC4655> and 3,4-dihydro pyrrolo[l,2-tf]pyrazine <1997T9341> undergo 1,3-dipolar cycloadditions with a number of dipolarophiles. For example, the ylide 178 reacts with propargylic ester 179 to give the tricyclic derivative 180 (Equation 43). 

One interesting example of this type of synthesis has been reported. 6-Phenyl-5//-5,7(6F/)-pyrrolo[3,4-/>]pyrazine (515) underwent electrolytic reduction in the presence of chlorotrimethylsilane to give the (unisolated ) substrate (516) that reacted with methyl acrylate (minimal detail) to afford a mixture of methyl 8-anilino-5-oxo-l,5-dihydro-6-quinoxalinecarboxylate (517) and methyl 5-ani-lino-8-oxo-4,8-dihydro-6-quinoxalinecarboxylate (517a) (17% and 21%, respectively, after separation). 

The l,2,5-oxadiazolo[3,4-< ]pyrrolo[l,2- ]pyrazine derivative 185 was synthesized from the cr-chloroketone 184 and diaminooxazole 183. Some dihydro product 186 was also isolated (Equation 45) <1999CHE882>. 

Lunesta, (+)-(5iS )-6-(chlor/7ynVir -2-yl)-7-oxo-6.7-dihydro-5H-pyrrolo A-b pyrazin-5-y 1-carboxylate... 

Chemical Name 1-Piperazinecarboxylic acid, 4-methyl-, 6-(5-chloro-2-pyridinyl)-6,7-dihydro-7-oxo-5H-pyrrolo[3,4-b]pyrazin-5-yl ester... 

Pyrrolo 1,2-a pyrazin l-Propyl-3,4-dihydro- E6a, 678 [2-Acyl-furan + H2N-(CH2)2-NH2] Quinolin 3-Aminomethyl-5,6,7,8-tetrahydro- (Bis-Hydrochlorid) IV/lc, 143... 

Jeanmart, C., Cotrel, C. Synthese de (chloro-5 pyridyl-2)-6 methyl-4 piperazinyl-1) carbonyloxy-5 oxo-7 dihydro-6,7 5/7-pyrrolo [3,4-h] pyrazine. Compt. Rend. Acad. Sci. Paris Sen C1978, 287, 377-378. 

Treatment of the /3-ribofuranosylpyranone derivative 606 with 1,2- diami-noethane, and removal of the sugar-blocking groups, gave the 3,4-dihydro-6-(/3-D-ribofuranosyl)pyrrolo[l,2-a]pyrazine 699 (88JOC1401) (Scheme 178). 

The most known designer drugs are carphedone 4-chloro-2,5-dimethoxyphenethylamine (2C-C) i 5-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-yM-methylpiperazine-l-carboxylate (zopiclone or Z-drug) 4-(N,N-dimethylamino sulfonyl)-7-fluoro-2,l,3-benzoxadiazole (DBD-F) dimethyltryptamine (DMTA) diphenydramine 4-ethyl-2,5-dimethoxyphenethylamine (2C-E) 4-ethylthio-2,5-dimethoxyphenethylamine (2C-T-2) 4-fluoroamphetamine (4-FMP) indan-2-amine 4-iodo-2,5-dimethoxyphenethylamine (2C-I) 1 -(4-iodo-2,5-dimethoxyphenyl)propan-2-amine (DOI) 4-isopropylthio-2,5-dimethyoxyphenethylamine (2C-T-4) meperidine 2-methylamino-l-(3,4-methylenedioxyphenyl)butan-l-one (Bk-MBDB) l-(3,4-methylenedioxybenzyl)piperazine (MDBP) 1 -(3,4-methylenedioxyphenyl)butan-2-amine (BDB) N-methyl-3,4-methylenedioxymethamphetamine (MMDA-2) N-methyl-1 -(3,4-methylenedioxyphenyl)butan-2-amine (HMDMA) N-methyl-l-(3,4-methylenedioxyphenyl)butan-3-amine (HMDMA) methylphenidate 4-methoxymethamphetamine (PMMA) l-(4-methoxyphenyl)piperazine (4-MPP) 2-(6-methyl-2-p-tolylimidazol[l,2-9]pyridine-3-yl)acetamide (zolpidem) normeperidine 4-phenylbutylamine (4-PBA) 3-phenyl-1-peopyTamine (3-PPA) and 2,4,6-trimethoxyamphetamine (TMA-6). 

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