Hydrochloric Acid → HCID 178423746, compound

Participants

Reaction Steps

A solution of N-Triphenylmethyl-5-(4'-methyl-4-nitrobiphen-2-yl)tetrazole (0.115 g, 0.224 mmol) in MeOH/DMF (2 mL/12 mL) was submitted to hydrogenation at 40 psi H2 with 10% Pd on carbon (50 mg) at room temperature for 1 hour. The reaction was filtered through celite and the filtrate was concentrated in vacuo. The triphenyl methyl group had been lost during the hydrogenation. The crude 4-amino compound was dissolved in glacial acetic acid (3 mL) and added slowly to a cooled (0° C.) solution of NaNO2 (28.8 mg, 0.417 mmol) in conc. sulfuric acid (1 mL). The diazonium solution was stirred well for 2 hours then slowly added to a cooled (0° C.) solution of CuCl (0.449 g; 20 equiv) in conc. HCl. This mixture was stirred for 30 minutes and then poured over H2O and extracted with Et2O/EtOAc. The combined organic extracts were washed with H2O and brine, dried over MgSO4 and concentrated in vacuo. The product was purified by flash chromatography on a silica column eluting with Hex/EtOAc/HOAc (80:20;1) to afford 27 mg (45% for 2 steps) of 5-(4-chloro-4'-methyl-biphen-2-yl)tetrazole. The free tetrazole was dissolved in CH2Cl2 (3.5 mL) and NEt3 (0.035 mL, 2.5 equiv) and Ph3CCl (27 mg, 1.0 equiv) were added. After 30 minutes the reaction was diluted with Et2O washed with 10% citric acid, 1N NaOH and brine. The organic was dried over anhydrous MgSO4 and concentrated in vacuo to afford 51.2 mg (100%) of crude N-triphenylmethyl-5-(4-chloro-4'-methyl-biphen-2-yl)tetrazole. 1H NMR (300 MHz, CDCl3) δ2.26 (s, 3H), 6.91 (d, 6H), 6.94 (ABq, 4H), 7.20-7.25 (comp, 7H), 7.43 (dd, 1H), 7.99 (dd, 1H).

Provenance & Evidence