Research Article

Regioselective Thiocyanation of Aromatic and Heteroaromatic Compounds Using [2-(Sulfooxy)ethyl]sulfamic Acid as an Efficient, Recyclable Organocatalyst and Novel Difunctional Brønsted Acid

Table 2

Optimization of solvent in presence of SESA (1 mol%) for synthesis of 3-thiocyanato-1H-indole 1b.

EntrySolvent Time (min)Yield %

1H2O (5 mL)12065
2Ethanol (5 mL)2078
3H2O : ethanol (1  :  1, 5 mL)3576
4H2O : ethanol (1 : 1, 10 mL)5074
5H2O : ethanol (1 : 2, 5 mL)4081
6H2O : ethanol (1 : 3, 5 mL)3084
7H2O : ethanol (1 : 4, 5 mL)2093
8H2O : ethanol (1 : 4, 2 mL)297
9H2O : ethanol (1 : 5, 5 mL)2088
10H2O : ethanol (1 : 10, 5 mL)2087
11H2O : ethanol (2 : 1, 5 mL)4084
12H2O : ethanol (5 : 1, 5 mL)7082
13H2O : ethanol (2 : 3, 5 mL)5063
14MeCN15069
14MeOH6083
15CH2Cl215045
16THF15065
17AcOEt15045