Phenylacetylene → 7,8-Dimethoxy-1-methyl-5-(2-phenylethynyl)-1,3-dihydro-1,4-benzodiazepin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 240 mg (0.89 mmol) of 5-chloro-7,8-dimethoxy-1-methyl-1,3-dihydro-1,4-benzodiazepin-2-one XVIIIaa in 7 ml of CH3CN, add under an inert atmosphere 17 mg (0.1 mmol) of PdCl2, 30 mg (0.16 mmol) of CuI. Stir for 5 minutes, then add 68 mg (0.23 mmol) of PPh3, 185 μl of Net3 and 150 μl of phenylacetylene. Heat the mixture at 55° C. for 3 hours. Evaporate to dryness and purify by silica chromatography (AcOEt 1/hexane 1, then AcOEt). Recrystallize in EtOH. Yield: 45%. 1H-NMR (DMSO, 200 MHz): d 3.33 (s, 3H, NCH3), 3.70–3.91 (m, 7H, 1HCH2+20CH3), 4.50–5.60 (m, 1HCH2), 7.06 (s, 1H Ar), 7.32 (s, 1H Ar), 7.48–7.68 (m, 5H Ar). Mass: (M+H)+=335.16.

Provenance & Evidence