Ethyl chloroformate → 5-Ethoxycarbonylamino-2-((3R)-3-t-butoxycarbonylamino-1-pyrrolidinyl)fluorobenzene

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Reaction Steps

5-Amino-2-(3(R)-(t-butoxycarbonyl)aminopyrrolidin-1-yl)fluorobenzene (27.33 g, 0.093 M) was dissolved in dry pyridine (150 ml) and cooled under nitrogen with stirring to 0°. Ethyl chloroformate (11.01, 0.102 M) was added dropwise, and the mixture stirred 30 minutes at the same temperature. Ice-water (250 ml) was added, and stirring continued for 1 hour. The resulting precipitate was collected, washed thoroughly with water, and dried, to give the desired product of sufficient quality for use without purification (33.6 g). NMR (DMSO-d6) δ: 1.21 (t, 3H); 1.36 (s, 9H); 1.90 (m, 1H); 2.05 (m, 1H); 3.04 (m, 1H); 3.20 (m, 1H); 3.32 (m, 1H); 3.40 (m, 1H); 4.02 (br, 1H); 4.05 (q, 2H); 6.62 (t, 1H); 7.02 (d, 1H); 7.08 (d, 1H); 7.22 (d, 1H); 9.38 (br, 1H). MS (ESP): 368 (MH+) for C18H26FN3O4

Provenance & Evidence