Entry

Reaction condition

Yield (%)

Time

Ref.

1

Reflux ethanol or acetic acid

71

5 - 6 h

[30]

2

I₂ (10 mol%), H₂O, 100˚C, 1.01 × 10⁵ Pa

71

28 min

[15]

3

DBU, r.t.

-

-

[32]

4

SDS (20 mol%), water, 60˚C

98

3

[22]

5

TBAB, water

91

25 min

[23]

6

TBAB, solvent-free

91

21 min

[23]

7

TiO₂/, H₂O, 80˚C

88

30

[30]

8

SiO₂Cl, CH₂Cl₂, 40˚C

85

3.5

[28]

9

DBSA (25 mol%), H₂O:Ethanol, 80˚C

90

60 min

this work

10

DBSA (25 mol%), H₂O:Ethanol, MV

90

4.5 min

this work