Thioglycolic Acid → Benzimidazol-2-ylmethanethiol

HRID 2283137Notes

Reaction equation

HRID 2283137 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[SH:9][CH2:10][C:11](O)=O.[OH-].[Na+]>Cl>[NH:7]1[C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[N:8]=[C:11]1[CH2:10][SH:9]

Participants

5

Reactant 3

HCID 1133Thioglycolic Acid2×HCID 7243O-PhenylenediamineHCID 14798Sodium Hydroxide

Product 1

HCID 95983Benzimidazol-2-ylmethanethiolYield 93%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Conditions

Temperature
60 °C

Procedure

To 1,2-phenylenediamine (1.88 g, 17 mmol) in 50% v/v hydrochloric acid (20 ml) was added 2-mercaptoacetic acid (1.3 ml, 1.7 g, 19 mmol). The reaction mixture was heated, under nitrogen, at 60° C. then at 90° C. for 48 hours. Additional 2-mercaptoacetic acid (400 μA, 530 mg, 6 mmol) was added in this time. A sample was analyzed by HPLC. The reaction mixture was cooled and neutralized to pH 5 with 40% v/v NaOH. The resulting solid was washed with water (50 ml) and dried under vacuum to yield (1H-Benzo[d]imidazol-2-yl)-methanethiol 1.95 g, 93% yield, Rt=7.6 min, purity >95% together with disulfide (Rt=8.0 mins) 4%. 1H NMR (d6-DMSO, 400 MHz) 14.3 ppm (bs, 0.5H), 7.46 ppm (m, 2H), 7.13 (m, 2H), 4.17 ppm (s 0.1H). MS (Electrospray+) 164 m/z (M+), 131 m/z (M-SH).

Workup

  1. temperatureThe reaction mixture was cooled
  2. washThe resulting solid was washed with water (50 ml)
  3. customdried under vacuum

Sources & evidence

ORD record
ord-0e74028c18034ecf9b8a5f1067aa6708
Source dataset
uspto-grants-2015_09
Patent number
US09144757B2

Reaction notes

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