Diisopropylethylamine → 4-[2-(5,6-Diphenyl-furo[2,3-d]pyrimidin-4-ylamino)-ethyl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 69 (0.2 g, 0.57 mmol), 4-(2-amino-ethyl)-piperazine-1-carboxylic acid tert-butyl ester (0.26 g, 1.13 mmol) and DIEA (0.20 mL, 1.14 mmol) in 1-butanol (5 mL) was heated to 120° C. for 1.5 h. After concentration, the residue was purified by silica gel chromatography using 2-5% MeOH/DCM, to give 4-[2-(5,6-diphenyl-furo[2,3-d]pyrimidin-4-ylamino)-ethyl]-piperazine-1-carboxylic acid tert-butyl ester 71 (0.20 g). Compound 71 was subjected to 20 mL of 20% TFA/DCM at rt for 2 h, then the reaction was concentrated almost to dryness under reduced pressure, and purified by silica gel column chromatography using 0.1% MeOH/DCM containing 1 mL ammonium hydroxide, to give 72 (0.15 g). MS: 400.2(M+1). 1HNMR (DMSO-d6) ppm 8.36 (s, 1H), 7.61-7.33 (m, 10H), 5.49 (t, 1H, J=4.48 Hz), 3.45 (dd, 2H, J1=5.10 Hz, J2=5.84 Hz), 2.33 (t, 2H, J=5.80 Hz), 2.13 (br, 4H), 1.95 (br, 1H) (note: some peaks overlapped with water peak in DMSO-d6). 1HNMR (CCl3-d) ppm 8.43 (s, 1H), 7.60-7.50 (m, 6H), 7.50-7.26 (m, 4H), 5.39 (t, 1H), 3.54 (dd, 2H, J1=5.05 Hz, J2=6.20 Hz), 2.73 (t, 4H, J=4.71 Hz), 2.44 (t 2H, J=5.91 Hz), 2.28 (br, 4H), 1,87 (br, 1H).

Provenance & Evidence