Acetyl chloride → HCID 59556726, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-(benzyloxycarbony)-3-methy-5,6,7,8-tetrahydroimidazo[1,2-a] pyrazine-2-carboxylic acid (370 mg, 1.173 mmol) in DCM (10m1) was added oxalyl chloride (2.054 ml, 23.47 mmol) and DMF (5 uL). The reaction was stirred for one hour and concentrated. A solution of (E)-3-chloro-N′-hydroxy-4-isopropoxybenzimidamide (268 mg, 1.173 mmol) in pyridine (10.00 ml) was added and the reaction was stirred at room temperature for 30 minutes. The reaction was treated with acetyl chloride (0.092 ml, 1.291 mmol) and then was heated at 115° C. under nitrogen for 4 hours. The reaction was cooled, concentrated and partitioned between saturated Na2CO3 and methylene chloride. The organic layer was washed with water, dried (sodium sulfate), filtered and concentrated under reduced pressure. The residue was purified on silica gel using 80:20/methylene chloride:ethyl acetate as the eluant to yield 2-[3-(3-Chloro-4-isopropoxy -phenyl)-[1,2,4] oxadiazol-5-yl] -3-methyl-5,6-dihydro-8H-imidazo[1,2-a] pyrazine-7-carboxylic acid benzyl ester (173 mg, 29%) as an off-white solid. LCMS (Table 1, Method a) Rl=4.34 min, m/z 508.24 (M+H)+; 1H NMR (400 MHz, DMSO-d6)δ 7.98 (d, 1 H), 7.93 (d,d, 1 H), 7.35 (m, 6H), 5.12 (s, 2H), 4.78 (m, 1 H), 4.66 (s,broad, 2H), 3.99 (m, 2H), 3.88 (s, broad, 2H), 2.57 (s, 3H), 1.31 (d, 6H).

Provenance & Evidence