1,1-Dimethylethyl N-(5-ethynyl-2,2-dimethyl-1,3-dioxan-5-yl)carbamate → Tert-butyl 5-(5-(5-(3-chloro-4-propoxy phenyl)-1,2,4-oxadiazol-3-yl)benzofuran-2-yl)-2,2-dimethyl-1,3-dioxan-5-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

A solution of the product of Step C (0.1 g; 0.22 mmol) and tert-butyl 5-ethynyl-2,2-dimethyl-1,3-dioxan-5-ylcarbamate (0.056 g; 0.22 mmol) in a mixture of DMF and DIPEA (3 ml:0.3 ml) was degassed with N2 and Cl2Pd(PPh3)4 (0.025 g) was added, followed by catalytic amount of CuI. The mixture was stirred overnight at 45° C. under N2, diluted to 20 ml with saturated NH4Cl and extracted with EtOAc (40 ml). The organic layer was separated, dried over MgSO4 and filtered. The filtrate was distilled off and the residue was purified by FCC (SiO2, hexane/EtOAc) to give the title compound (0.11 g, 78%), as pale paste. 1H-NMR (CDCl3) 8.34 (d, 1H, J=1.29 Hz); 8.24 (d, 1H, J=2.13 Hz); 8.08 (t, 1H, J=1.56 Hz); 8.05 (t, 1H, J=1.56 Hz); 7.53 (d, 1H, J=8.67 Hz); 7.03 (d, 1H, J=8.67 Hz); 6.75 (s, 1H); 4.26-4.19 (m, 4H); 4.06 (t, 2H, J=5.49 Hz); 1.94-1.87 (m, 2H); 1.41 (s, 9H); 1.36 (s, 6H); 1.1 (t, 3H, J=7.44 Hz).

Provenance & Evidence