A rapid and versatile one-pot, 2 × 10 min microwave protocol for the preparation of N-1 and C-6 decorated 3,5-dichloro-2(1H)-pyrazinones was developed. Comparable reaction sequences using classical conditions require about 1–2 days of heating. The α-aminonitrile was first generated in a Strecker reaction and thereafter cyclized under microwave heating. The microwave approach developed offers the possibility of efficiently generating and utilizing functionalized 3-amino-5-chloro-2(1H)-pyrazinone-N-1-carboxylic acids as β-strand inducing core structures in a medicinal chemistry context. To illustrate the usefulness of the method, the synthesis of two novel 2(1H)-pyrazinone-containing Hepatitis C virus NS3 protease inhibitors is reported.
[EN] [1,2,4]TRIAZOLO[4,3-A]PYRAZIN-8-ONE DERIVATIVES<br/>[FR] DÉRIVÉS DE [1,2,4]TRIAZOLO[4,3-A]PYRAZIN-8-ONE
申请人:LILLY CO ELI
公开号:WO2019156861A1
公开(公告)日:2019-08-15
The present invention provides a compound of Formula I: wherein R1 is methyl, ethyl or cyclopropyl; R2 is hydrogen, methyl, or ethyl; R3 is methyl or AA; and R4 is C2-C4 alkyl, BB; or a pharmaceutically acceptable salt thereof; for use as a PDE1 inhibitor.