4-Chloro-1,1-dimethoxybutane → Indole

HRID 1034464

Reaction equation

HRID 1034464 reaction equation
Cl.C(OC(=O)[C:6]1[CH:11]=[CH:10][C:9]([NH:12]N)=[CH:8][CH:7]=1)C.CO[CH:17](OC)[CH2:18]CCCl>C(O)C.O>[NH:12]1[C:9]2[C:10](=[CH:11][CH:6]=[CH:7][CH:8]=2)[CH:18]=[CH:17]1

Participants

4

Reactant 2

HCID 1225364-Chloro-1,1-dimethoxybutaneHCID 12414202Ethyl 4-hydrazinylbenzoate hydrochloride

Product 1

HCID 798IndoleYield 68.5%

Reagents, catalysts & solvents 1

HCID 19096565Water ethanolSolvent

Procedure

A solution of ethyl-p-hydrazinobenzoate hydrochloride (10 g, 46 mmol) and 4-chlorobutanal dimethyl acetal (7.8 g, 46 mmol) in ethanol/water (5:1, 500 ml) was heated at reflux for 2 h. The solvent was removed under vacuum and the residue chromatographed through silica-gel eluting with dichloromethane/ethanol/ammonia (40:8:1) to give the title-indole as an oil (3.69 g). The hydrogen maleate salt was prepared, mp 127° C.; (Found: C, 59.46; H, 5.96; N, 8.47. C13H16N2O2.C4H4O4 requires C, 59.68; H, 5.93; N, 8.54%), m/e 232 (M+), δ(360 MHz, D2O) 1.43 (3H, t, J=7.1 Hz, Me); 3.21 (2H, t, J=7.0 Hz, CH2); 3.37 (2H, t, J=7.0 Hz, CH2); 4.42 (2H, q, J=7.1 Hz, CH2); 6.23 (2H, s, maleate-H); 7.40 (1H, s, indole-H); 7.56 (1H, d, J=8.8 Hz, aromatic-H); 7.88 (1H, dd, J=1.6 and 8.8 Hz, aromatic-H); 8.38 (1H, d, J=1.6 Hz, aromatic-H).

Workup

  1. temperatureat reflux for 2 h
  2. customThe solvent was removed under vacuum
  3. customthe residue chromatographed through silica-gel
  4. washeluting with dichloromethane/ethanol/ammonia (40:8:1)

Sources & evidence

ORD record
ord-7c19ddf45d6d492c8d718a60e1e8f57d
Source dataset
uspto-grants-1994_05
Patent number
US05317103

Linked notes

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