Isoquinoline, 3-amino-4,5,6,7-tetrahydro

Reaction of 2-chloro-6,7-dihydro-4//-pyrimido[6,1 -a]isoquinolin-4-ones with liquid NH3 in a pressure bomb at 85 °C for 4h, and with primary and secondary amines in boiling CHCI3 (98MIP15), and anilines in boiling i-PrOFI (00MI17) yielded 2-amino-6,7-dihydro derivatives or their 2,3,6,7-tetrahydro-2-imino tautomers. 

The side chain C=C double bond of 2,3,4,6,ll,lln-hexahydro-l//-pyrazino[l,2-i]isoquinoline-l,4-diones 354 was saturated by catalytic hydrogenation over Pd/C catalysts in EtOH to give 355 (98MIP7). 7-(2-Pyridylmethyl)amino derivative was obtained by reduction of 7-[(2-pyridylmethylene)amino]-2,3,11,11 n-tetrahydro-6//-pyrazino[l, 2-i]isoqui-noline-l,4-dione (356) with NaBH4 in EtOH at ambient temperature for 24 h. 

Among the amines that have been resolved with (-)-DAG are a-phenylethylamine (a-methylbenzenemethanamine),s [R-(R, R )]-2-amino-l-(4-nitrophenyl)-l, 3-propanediol,61,2,3,4,5,6,7,8-octahydro-l-(4-methoxyphenylmethyl)isoquinoline, 3-methoxymorphinan, 1,2,3,4-tetrahydro-7-methoxy-4-phenylisoquinoline, 3-hydroxy-A7-methyl-... 

CN 7-amino-4,5,6-triethoxy-3-(5,6,7,8-tetrahydro-4-methoxy-6-methyl-l,3-dioxoIo[4,5-g]isoquinolin-5-yl)-1 (3//)-isobenzofuranone... 

Treatment of 3-[(3-chloropropyl)amino]-l,4-dihydroisoquinoline hydroiodide (191), prepared from 3-methylthio-l,4-dihydroisoquinoline hydroiodide and 3-chloropropylamine, with a mole equivalent of boiling 1 N ethanolic sodium ethylate for 24 h, then with picric acid afforded 3,4,6,11-tetrahydro-2//-pyrimido[l,2-6]isoquinoline picrate (192) (88MI3). 

Ethyl 4-oxo-7,8,9,10-tetrahydro-4//-pyrimido[l,2-b]isoquinoline-3-carboxy-lates (196) were prepared by the cyclization of diethyl [(5,6,7,8-tetrahydro-3-isoquinolinyl)amino]methylenemalonate (195) in boiling diphenyl ether (83KGS1279 84KFZ931) and by heating in polyphosphoric acid ethyl ester (88MI5). 

Heating a mixture of 2-(carboxymethyl)benzoic acids and 3-amino-propanol in o-dichlorobenzene in the presence of p-toluenesulfonic acid yielded 2,3,4,6-tetrahydro[l,3]oxazino[3,2-b]isoquinolin-6-ones (78BEP 866987, 78GEP2756067 79CPB2372). Similar reaction between o-benzoylphenylacetic acid and 3-aminopropanol in toluene resulted in 11 b-phenyl-2,3,4,6,7,116-hexahydro[l,3]oxazino[2,3-a]isoquinolin-6-one (71MI1). Reaction of 2-(2-bromoethyl)benzaldehyde and 3-aminopropanol in ethanol led to 2,3,4,6,7,llb-hexahydro[l,3]oxazino[2,3-a]isoquinoline (61AP645). 

Chemical Name 8-Amino-l,2,3,4-tetrahydro-2-methyl-4-phenyl-isoquinoline maleate... 

A solution of N-(2-aminobenzyl)-l-phenyl-2-methylaminoethanol-l was prepared by the reaction of a-bromo-acetophenone and (2-nitrobenzyl)methylamine, followed by hydrogenation of the nitro group by means of nickel on diatomaceous earth at room temperature and reduction of the CO group by means of sodium borohydride. The intermediate thus produced was dissolved in 100 ml of methylene chloride and introduced dropwise into 125 ml of sulfuric acid at 10° to 15°C. After a short standing, the reaction mixture was poured onto ice and rendered alkaline by means of a sodium hydroxide solution. By extraction with ether, there was obtained l,2,3,4-tetrahydro-2-methyl-4-phenyl-8-amino-isoquinoline. The base is reacted with maleic acid to give the maleate melting point of the maleate 199° to 201°C (from ethanol). 

In earlier investigations by the author, nerve growth agents consisting of 1,2,3,4-tetrahydro-isoquinoline, (I), (3), and azo-amino acid derivatives, (II), (4), were prepared and used in the treatment of neurological disorders. 

Ethan 2-[2-(3-Cyclohexenyl)-l,3-dioxolan-2-yl]-l-diazo- E14b, 985 (aus 1-R — 1-NO — harnstoff) Isoquinolin 2-Amino-6,7-dimethoxy-1,2,3,4-tetrahydro- Elba, 501 (N —N-Aufbau)... 

Harnstoif l,l-Diethyl-3-(2-methoxy-phenyl)- E4, 340 (Cl - NR2) Isoquinolin 2-Amino-6,7-dimethoxy-1 -methyl-1,2,3,4-tetrahydro-E16a, 501 (N-N-Aufbau) Kohlensaure -ethylester-[2-(4-isopropyl-phenyl)-hydrazid]... 

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