3,4,5-Trichlorobenzene-1,2-diamine → 2-Amino-4,5,6-trichlorobenzimidazole

To a stirred solution of 3.62 mL of 5M BrCN/MeCN in 35 mL of H2O, was added dropwise a solution of 3,4,5-trichloro-1,2-phenylenediamine (13a) (3.478 g, 16.446 mmol) in 35 ml of MeOH. After the addition had been completed, stirring was continued at room temperature for 2 hr. The reaction mixture was concentrated to ~35 mL and was washed with EtOAc (50 mL).T he EtOAc phase was extracted with H2O (50 mL). The combined H2O phase was neutralized with sat. NaHCO3 solution to ~pH 8 and the resulting suspension was extracted with EtOAc (150 mL). The EtOAc phase was washed with a mixture of sat. NaHCO3 and sat. NaCl solution (20 mL/130 mL), dried (Na2SO4), and evaporated. The residue was dissolved in MeOH, decolorized with charcoal, and then recrystallized from MeCN to give 3.098 g (2 crops, 80%) of 13b as a slightly grey crystals. MP: 255°-258° C. MS: (El) m/e 234.9473 (100% M+ =234.9471). 1H NMR (DMSO-d6): d 11.25 (br s, 1,1-NH), 7.29 {s, 1,7(4)-H}, 6.75 (br s, 2,2-NH2). Anal. Calcd. for C7H4Cl3N3 : C 35.55, H 1.70, N 17.77, Found: C 35.72, H 1.78, N 17.89.

1. additionAfter the addition
2. concentrationThe reaction mixture was concentrated to ~35 mL
3. washwas washed with EtOAc (50 mL)
4. extractionhe EtOAc phase was extracted with H2O (50 mL)
5. extractionthe resulting suspension was extracted with EtOAc (150 mL)
6. washThe EtOAc phase was washed with a mixture of sat. NaHCO3 and sat. NaCl solution (20 mL/130 mL)
7. dry with materialdried (Na2SO4)
8. customevaporated
9. dissolutionThe residue was dissolved in MeOH
10. customrecrystallized from MeCN

ORDレコード

ord-217b8d606dfe4bdfa66dc3dd741ee50b

出典データセット

uspto-grants-1994_11

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05360795