Carbamic acid, (4'-amino-3,3'-dimethyl[1,1'-biphenyl]-4-yl)-,1,1-dimethylethyl ester synthesis

Yield:753475-22-8 59%

Reaction Conditions:

with N-ethyl-N,N-diisopropylamine in dichloromethane at 20;

Steps:

1 Synthesis of compound 12:

Put 4,4'-diamino-3,3'-dimethylbiphenyl (compound 11) (2.12g, 10.0mmol), di-tert-butyl dicarbonate (2.2g, 10.0mmol) and N,N-Diisopropylethylamine (1.3g, 10.0mmol) and 20mL of dichloromethane were stirred overnight at room temperature. The completion of the reaction was monitored by HPLC (rt 10.13 minutes). The solvent was distilled off under reduced pressure to obtain a crude product. Column (petroleum ether/ethyl acetate=5:1) was purified to obtain a white solid compound 12 with a yield of 59%.

References:

CN113582975,2021,A Location in patent:Paragraph 0103; 0124-0125; 0143