Cysteamine → S-Tritylcysteamine

HRID 1005259Notes

Reaction equation

HRID 1005259 reaction equation
[NH2:1][CH2:2][CH2:3][SH:4].[C:5]1([C:11]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)O)[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1>Cl.C(O)(=O)C>[C:5]1([C:11]([C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=2)([C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)[S:4][CH2:3][CH2:2][NH2:1])[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1

Participants

5

Reactant 2

HCID 6058CysteamineHCID 6457Triphenylcarbinol

Product 1

HCID 262764S-TritylcysteamineYield 90%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 313Hydrochloric AcidSolvent2×

Procedure

A solution of 2-aminoethanethiol.HCl 80 (11.4 g, 100 mmol), triphenylmethanol (TrOH, 26.0 g, 100 mmol) in HCl (37%, 44.8 mL) and acetic acid (280 mL) was stirred for 5 h at 40° C. The reaction mixture was concentrated in vacuo and the resulting white solid was washed with ether and dissolved in H2O/CH2Cl2 (1:1). After adjusting the pH of the aqueous layer to ca. 14 with 1 N NaOH, the desired compound was removed by extraction. The combined organic layers were dried (K2CO3), filtered, and concentrated in vacuo to provide a white solid, S-(triphenylmethyl) 2-aminoethanethiol (28.8 g, 90.0 mmol, 90% from 80). Rf =0.50 (1:9 MeOH/CH2Cl2); 1H NMR (DMSO-d6) δ7.35-7.20 (m, 15H), 2.43 (t, J=6.1, 2H), 2.15 (t, J=5.9, 2H). To a solution of S-(triphenylmethyl) 2-aminoethanethiol (3.00 g, 9.40 mmol) and triethylamine (951 mg, 9.40 mmol) in dry CH2Cl2 (30 mL) was added bromoacetyl bromide (1.90 g, 9.40 mmol) over 15-20 min at -20°. The reaction mixture was stirred at -20° for 30 min and at room temperature for 1 h. To this mixture was added an additional equivalent of S-(triphenylmethyl) 2-amninoethanethiol (3.00 g, 9.40 mmol) and triethylamine (951 mg, 9.40 mmol). After stirring for 16 h at room temperature, the reaction mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (1:99 MeOH/CH2Cl2) to give compound 81 as a white foam (4.64 g, 6.95 mmol, 67% from amine 80). Rf 0.60 (1:9 MeOH/CH2Cl2); 1H NMR (DMSO-d6) δ7.77 (t, J=6.1, 1H), 7.35-7.20 (m, 30H), 2.97 (dd, J=6.0, 5.9, 2H), 2.86 (s, 2H), 2.35 (t, J=6.1, 2H), 2.18 (m, 4H). See Photaki et al., J. Chem. Soc. (c) 2683-2687 (1970); Bryson, N. J., Neutral technetium (v) complexes with N,S-donor chelates. Ph.D. thesis, Massachusetts Institute of Technology, Cambridge, Mass. (1988).

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. washthe resulting white solid was washed with ether
  3. dissolutiondissolved in H2O/CH2Cl2 (1:1)
  4. customthe desired compound was removed by extraction
  5. dry with materialThe combined organic layers were dried (K2CO3)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-7a8ffd2901ad4f7a9148266c60061299
Source dataset
uspto-grants-2000_04
Patent number
US06054114

Reaction notes

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