N-((1,1-dimethylethoxy)carbonyl)-beta-alanine → HCID 68185403, compound

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Reaction Steps

A flask was charged with N-{[(1,1-dimethylethyl)oxy]carbonyl}-β-alanine (227 mg, 1.200 mmol) and HATU (494 mg, 1.300 mmol) then filled with N,N-dimethylformamide (DMF) (5 mL). DIPEA (0.524 mL, 3.00 mmol) was added and the resulting pale yellow solution was stirred for 5 min. 1-Methylethyl {(2S,4R)-1-acetyl-6-[(hydroxyamino)(imino)methyl]-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl}carbamate (for a preparation, see Intermediate 56) (348 mg, 1 mmol) in N,N-dimethylformamide (DMF) (5 mL) was then added via syringe. The resulting mixture was stirred at room temperature for 30 min, at 110° C. for 5 h then cooled to room temperature and partitioned between AcOEt and water/brine (1/1). The layers were separated and the aqueous phase was extracted with AcOEt. The combined organic phases were washed with water/brine (1/1) (3×) then dried over MgSO4 and concentrated in vacuo. Purification of the residue by SP4 using 25 G silica cartridge (gradient: 23 to 73% AcOEt in Hexanes), gave 1-methylethyl((2S,4R)-1-acetyl-6-{5-[2-({[(1,1-dimethylethyl)oxy]carbonyl}amino)ethyl]-1,2,4-oxadiazol-3-yl}-2-methyl-1,2,3,4-tetrahydro-4-quinolinyl)carbamate (260 mg, 0.518 mmol, 51.8% yield) as a pale orange foam. LCMS (method G): Retention time 1.04 min, [M+H]+=502.0

Provenance & Evidence