1: 91 percent / tetrabutylammonium iodide; K2CO3 / acetone / 18 h / 65 °C 2: 78 percent / 2,6-di-tert-butyl-4-methylphenol / m-xylene / 15 h / 140 °C View Scheme

potassium carbonate

1: 94 percent / K2CO3 / acetone 2: 92 percent / Pd(OAc)2, (Tol)3P, Et3N / acetonitrile / Heating 3: 98 percent / Zn, AcOH 4: 96 percent / pyridine / CH2Cl2 5: 92 percent / triphosgene, Et3N / CH2Cl2 6: 1.) Bu3SnH, AIBN; 2.) dil. HCl / 1.) MeCN, reflux; 2.) 0 deg C 7: NaOH / H2O; tetrahydrofuran 8: H2 / Pd-C / methanol View Scheme

1: 94 percent / K2CO3 / acetone 2: 92 percent / Pd(OAc)2, (Tol)3P, Et3N / acetonitrile / Heating 3: 98 percent / Zn, AcOH 4: 96 percent / pyridine / CH2Cl2 5: 92 percent / triphosgene, Et3N / CH2Cl2 6: 1.) Bu3SnH, AIBN; 2.) dil. HCl / 1.) MeCN, reflux; 2.) 0 deg C 7: NaOH / H2O; tetrahydrofuran View Scheme

di-isopropyl azodicarboxylate; triphenylphosphine in tetrahydrofuran T=0 - 20°C; Mitsunobu reaction;

1: 95 percent / triphenylphosphine; diisopropyl azodicarboxylate / tetrahydrofuran / 0 - 20 °C 2: 93 percent / FeCl3*6H20; Carbon bBlack; hydrazine / methanol / 2 h / 70 °C View Scheme

1: 94 percent / K2CO3 / acetone 2: 92 percent / Pd(OAc)2, (Tol)3P, Et3N / acetonitrile / Heating 3: 98 percent / Zn, AcOH 4: 96 percent / pyridine / CH2Cl2 5: 92 percent / triphosgene, Et3N / CH2Cl2 6: 1.) Bu3SnH, AIBN; 2.) dil. HCl / 1.) MeCN, reflux; 2.) 0 deg C 7: NaOH / H2O; tetrahydrofuran 8: H2 / Pd-C / methanol 9: DIBAL / CH2Cl2 / -78 °C 10: pyridine / CH2Cl2 / 0 °C 11: NaN3 / dimethylformamide 12: H2 / 10percent Pd-C / methanol View Scheme