Dimethylformamide → HCID 66832680, compound

Participants

Reaction Steps

A solution of (R)-2-amino-6-borono-2-((R)-pyrrolidin-3-yl)hexanoic acid (Example 35-A, Step 5, 200 mg, 0.8 mmol) and triethylamine (900 uL, 6 mmol) in N,N-dimethylformamide (4 mL, 50 mmol) was treated with 4-chlorobenzene isocyanate-(280 mg, 1.8 mmol) in a single portion. After stirring at room temperature for 30 min, the reaction was diluted with 1 N HCl (20 mL) and washed with ethyl acetate (20 mL). The aqueous solution was concentrated and purified by HPLC to give 2-amino-6-borono-2-((S)-1-(4-chlorophenylcarbamoyl)pyrrolidin-3-yl)hexanoic acid (0.021 g, 6%). 1H NMR (400 MHz, D2O, Mixture of diastereoisomers) δ 7.26 (d, J=8.1 Hz, 2H), 7.14 (d, J=8.1 Hz, 2H), 3.70-3.48 (br, m, 2H), 3.99-3.08 (br, m, 2H), 2.79-2.65 (br, m, 1H), 2.30-1.75 (br. m, 4H), 1.54-1.44 (br. m, 2H), 1.35-1.27 (br. m, 1H), 0.87 (t, J=6.5 Hz, 2H),; MS (ESI+) found for C17H25ClBN3O5 m/z (M-water+H)+ 380.2; MS; (M-water+Na)+ 403.3

Provenance & Evidence