5,11-Dihydro-6H-pyrido[2,3-b][1,4]benzodiazepine-6-thione synthesis

Yield:1204296-84-3 74%

Reaction Conditions:

with Lawessons reagent at 150; for 0.5 h;

Steps:

5.1.1

Example 1Synthesis of 6-(methylthio)-11H-benzo[e]pyrido[3,2-b][1,4]diazepineStep 1. Synthesis of 5H-benzo[e]pyrido[3,2-b][1,4]diazepine-6(11H)-thioneTo a mixture of 5H-benzo[e]pyrido[3,2-b][1,4]diazepin-6(11H)-one (0.2 g, 0.948 mmol) in Dowtherm A (3 mL) was added Laweson's reagent (0.384 g, 0.948 mmol). The reaction mixture was heated at 150° C. for 30 minutes. Once the reaction was complete the reaction mixture was allowed to cool to room temperature and a 1:2 mixture of EtOAc and hexanes (10 ml) was added. The solid was filtered, washed with a 1:2 mixture of EtOAc and hexanes (10 ml) and dried under high vacuum. The desired product, 5H-benzo[e]pyrido[3,2-b][1,4]diazepine-6(11H)-thione was obtained as a reddish brown solid (0.16 g, 74%). M.p.=178-180° C.; 400 MHz ¹H NMR (DMSO-d₆) δ: 11.99 (s, 1H), 10.4-9.6 (br s, 1H), 8.40 (s, 1H), 8.0-7.8 (m, 2H), 7.47-7.3 (m, 2H), 7.08-6.9 (m, 2H); LCMS [M+H]: 228.

References:

US2011/245236,2011,A1 Location in patent:Page/Page column 93