From: A facile and one-pot synthesis of new tetrahydrobenzo[b]pyrans in water under microwave irradiation

Entry | Solvent | Condition | Conventional | MWI | ||
---|---|---|---|---|---|---|

Time (h) | Yield^{a} (%) | Time (h) | Yield^{a} (%) | |||

1 | – | R.T | 12.0 | – | 6.0 | – |

2 | – | Heat | 10.0 | – | 6.0 | – |

3 | n-Hexane | R.T | 10.0 | – | 4.0 | – |

4 | Toluene | R.T | 10.0 | – | 4.0 | – |

5 | THF | R.T | 5.0 | 5 | 2.5 | 13 |

6 | CH_{3}CN | R.T | 5.5 | 6 | 3.0 | 10 |

7 | DMF | R.T | 6.0 | 9 | 2.5 | 15 |

8 | MeOH | R.T | 3.5 | 67 | 2.5 | 71 |

9 | EtOH | R.T | 2.5 | 71 | 0.5 | 84 |

10 | H_{2}O | R.T | 3.0 | 79 | 0.20 | 98 |