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Table 3 Comparison of isolated yields for microwave-assisted and conventional Hantzsch synthesis of thiazolyl coumarins 10

From: Microwave-assisted synthesis and antioxidant properties of hydrazinyl thiazolyl coumarin derivatives

Entry Compound Yield% under microwave irradiation Yield% using traditional conditions
1 10a 74 70
2 10b 80 72
3 10c 71 80
4 10d n/a 72
5 10e 72 78
6 10f 72 70
7 10g 71 70
8 10h 79 75
  1. Isolated yield after microwave dielectric heating in EtOH at 60°C for 10 min (hold time) in a sealed tube using a CEM Discover single-mode microwave synthesizer by moderation of the initial magnetron power (30 W), followed by treatment with aqueous base and purification by recrystallization. Isolated yield after reaction by traditional conductive heating at reflux in EtOH–CHCl3 for 1–4 h, basification with NH3 (aq) and purification by recrystallization (see reference 20 for details). n/a Experiment not investigated.