3-Benzyl-5-chloro-4-oxo-3,4-dihydro-pyrrolo[2,1-f][1,2,4]triazine-2-carbaldehyde → (+/-)-3-Benzyl-5-chloro-2-(1-hydroxy-allyl)-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one

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Reaction Steps

To a solution of 3-benzyl-5-chloro-4-oxo-3,4-dihydro-pyrrolo[2,1-f][1,2,4]triazine-2-carbaldehyde (Example 22 E, 287 mg, 1 mmol) in THF (4 mL) at −50° C. was added a vinylmagnesium bromide solution (1.5 mL of 1 M solution) under Ar. The mixture was stirred for 2 h, slowly warmed to rt over 2 h and stirred at rt for 30 min. The reaction mixture was quenched by the addition of 0.2 mL of HOAc followed by water (15 mL) and EtOAc (40 mL). The organic layer was dried over MgSO4 and concentrated in vacuo to obtain the crude title compound as a brown solid (315 mg, 100%) which was used in the next step without any further purification: 1H NMR (CDCl3) δ 7.10–7.50 (m, 6H), 6.47 (s, 1H), 6.01 (m, 1H), 5.05–5.25 (m, 4H), 5.05 (s, 1H); 13C NMR (CDCl3): δ 153.9, 149.8, 135.9, 135.4, 128.8, 127.7, 126.3, 119.8, 118.5, 113.6, 111.6, 70.4, 44.1.

Provenance & Evidence