Aluminium lithium hydride → 7-bromo-4-(2-hydroxyethyl)-3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)-one

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Reaction Conditions

Reaction Steps

Ethyl 2-(7-bromo-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-4-yl)acetate (1.23 g, 4.1 mmol) was treated with THF (30 mL), cooled to 0° C. and treated with LiAlH4, 1.0 M solution in THF (4.1 mL, 4.1 mmol) and stirred at 0° C. for 30 min. The reaction was quenched by slow dropwise addition of an aq. solution of sodium potassium tartrate and stirred at RT for 30 min. The resulting mixture was extracted with EtOAc (3×25 mL), washed with brine and dried over MgSO4, filtered and concentrated in vacuo to afford crude 7-bromo-4-(2-hydroxyethyl)-3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)-one (987 mg, 3.81 mmol, 93% yield) as a white crystalline solid: 1H NMR (400 MHz, MeOH-d4) δ ppm 7.10 (1H, s), 6.83 (1H, s), 4.47 (1H, tt, J=7.1, 3.7 Hz), 3.85 (1H, dd, J=13.2, 4.2 Hz), 3.68 (1H, dt, J=11.2, 5.6 Hz), 3.46-3.56 (2H, m), 1.91-2.07 (2H, m). m/z (ESI, +ve ion) 259.0/261.0 (M+H)+.

Provenance & Evidence