1: 85 percent / pyridine / 25 h / 65 °C 2: 1) bis-trimethylsilylacetamide; 2) trimethylsilyl trifluoromethanesulfonate / 1) acetonitrile, 70 deg C, 15 min; 2) acetonitrile, 70 deg C, 4 h 3: ammonia / methanol / 12 h / 40 °C View Scheme

1: 85 percent / pyridine / 25 h / 65 °C 2: 1) bis-trimethylsilylacetamide; 2) trimethylsilyl trifluoromethanesulfonate / 1) acetonitrile, 70 deg C, 10 min; 2) acetonitrile, 70 deg C, 5 h 3: sodium methoxide / methanol / 1.25 h / Ambient temperature View Scheme

1: 85 percent / pyridine / 25 h / 65 °C 2: 1) bis-trimethylsilylacetamide; 2) trimethylsilyl trifluoromethanesulfonate / 1) acetonitrile, 70 deg C, 15 min; 2) acetonitrile, 70 deg C, 4 h 3: ammonia / methanol / 12 h / 40 °C View Scheme