6-Formyl-2- perhydropyrido pyrazine

Reduction of a 7-(2-oxoethyl) derivative with NaBH4 in EtOH at room temperature gave 7-(2-hydroxyethyl)-2-(2-pyrimidinyl)perhydropyrido[l, 2-u]pyrazine (99MIP6). Reduction of 7-formyl-8-[(4-cyanophenyl)methoxy]-1,3,4,6,11,1 lu-hexahydro-2//-pyrazino[l,2-A]isoquinoline-l,4-dione with NaBH4 yielded a 7-hydroxymethyl derivative (98MIP7). 

Hydroxy group of rru -7,9u-H-7-(prepared from 7-formyl-2-(2-pyrimidyl)perhydropyrido[l,2-u]pyrazine by the treatment with MeOCH2P(Ph)3Cl in the presence of -Pr2NH in THF at 0°C, than with BuLi at room temperature (99MIP6). 

The 7-(2-oxoethyl) derivative was prepared from 7-formyl-2-(2-pyrimidyl)perhydropyrido[l,2- ]pyrazine by the treatment with MeOCHzP(Ph)3Cl in the presence of Pr 2NH in THF at 0°C, then with BuLi at room temperature < 1999WO99/020622>. Reaction of a 7-mesyloxymethyl group in perhydropyrido[l,2-tf Ipyrazine with NaCN in DMF at 110°C gave a 7-cyanomethyl derivative, which was converted into a 2-oxoethyl group by treatment first with DIBAL-H, then with 2M HC1. The 2-oxoethyl group was reacted with 4-FC6H4MgBr in THF at — 10°C to yield a... 

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