Skip to main content

Table 1 Optimization of conditions of the synthesis 9a a

From: Organocatalysis in heterocyclic synthesis: DABCO as a mild and efficient catalytic system for the synthesis of a novel class of quinazoline, thiazolo [3,2-a]quinazoline and thiazolo[2,3-b] quinazoline derivatives

Entry a Base Solvent Time(min) Yield (%)
1 DABCO EtOH 5 81
2 piperidine EtOH 30 67
3 morpholine EtOH 25 61
4 DBU EtOH 15 55
5 L-proline EtOH 40 69
6 K2CO3 EtOH 60 none
7 DABCO CH3CN 15 35
8 DABCO DMF 5 46
9 DABCO Dioxane 5 51
10 DABCO MeOH 5 68
  1. a Reaction conditions: methyl-2-(2-thiocyanatoacetamido)benzoate (4) (5 mmol), benzylidene malononitriles 8a (5 mmol), and base (10 mol %) in solvent (25 mL) under reflux for the given time.