5-bromophthalazin-1(2H)-one synthesis

Yield:-

Steps:

Multi-step reaction with 2 steps
1.1: n-butyllithium; 2,2,6,6-tetramethyl-piperidine / hexane; tetrahydrofuran / 1 h / -50 °C / Inert atmosphere
1.2: -50 - 20 °C / Inert atmosphere
2.1: hydrazine / ethanol / 2.07 h / 80 °C / Inert atmosphere

References:

Krishnananthan, Subramaniam;Smith, Daniel;Wu, Dauh-Rurng;Yip, Shiuhang;Gunaga, Prashantha;Mathur, Arvind;Li, Jianqing [Journal of Organic Chemistry,2016,vol. 81,# 4,p. 1520 - 1526]