Oxalyl chloride → 10a-(4-methoxyphenyl)-1-[(3-methyl-1,2-oxazol-4-yl)carbonyl]-7-nitro-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one

Participants

Reaction Conditions

Reaction Steps

To generate the acid chloride, oxalyl chloride (600 μL, 7.0 mmol) and DMF (1 drop) were added to 3-methyl-1,2-oxazole-4-carboxylic acid (441 mg, 3.47 mmol) in CH2Cl2 (6 mL) at 0° C. The suspension was allowed to stir 15 minutes at 0° C. followed by 1 hour at room temperature. The resulting solution was concentrated in vacuo (without heating) to give a oil that was further dried under nitrogen. To a chilled suspension of the acid chloride (generated as above, 3.47 mmol) in pyridine (3 mL) was added 10a-(4-methoxyphenyl)-7-nitro-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one (190 mg, 0.58 mmol) in pyridine (4 mL). The reaction mixture was stirred at 0° C. to room temperature for 45 minutes and was then quenched with water (15 mL) and extracted with CH2Cl2 (4×15 mL). The organic fractions were washed with brine, dried (MgSO4), filtrated and concentrated to yield a residue that was purified by triturating with acetone to give 10a-(4-methoxyphenyl)-1-[(3-methyl-1,2-oxazol-4-yl)carbonyl]-7-nitro-2,3,10,10a-tetrahydro-1H,5H-imidazo[1,2-a]pyrrolo[1,2-d]pyrazin-5-one (124) (170 mg, yield 68%).

Provenance & Evidence