Patent ID: 9688610
Date: 2017-06-27
CPC Classifications: C07C

Claim:
1. A method for preparing a compound of formula 1, comprising steps of: (1) contacting a compound of formula 2 with acetic anhydride to obtain a compound of formula 3; (2) contacting the compound of formula 3 with a compound of formula 4 to obtain a compound of formula 5; (3) contacting the compound of formula 5 with polyphosphoric acid to obtain a compound of formula 6; (4) contacting the compound of formula 6 with borane-tetrahydrofuran to obtain a compound of formula 7; (5) contacting the compound of formula 7 with sodium hydroxide to obtain a compound of formula 8; and (6) contacting the compound of formula 8 with a compound of formula 9 to obtain the compound of formula 1,