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Part-IIImpact of Microwave…An efficient and convenient method has been developed for the preparation of2,4(1H,3H)-quinazolinediones 67 and 2-thioxoquinazolinones 68(35 compounds).Substituted methyl anthranilates have been reacted with various iso(thio)cyanates inDMSO/H 2 O without any catalyst or base by using microwave irradiation to generatediversity on the 2,4(1H,3H)-quinazolinediones or 2-thioxoquinazolinones. A variety ofsubstrates can participate in the process to yield products in good yields and high purity,making this methodology suitable for library synthesis of NCE’s in drug discoveryefforts. 59OOONCOR 1 + R 2NH 2DMSO/H 2 OMWI, 120 o C, 20 minNHNR 2O67R 1 R 1 = H, 5-FR 2 = 2-F 3 CPh, 3-F 3 CPh,4-FPh, 4-BrPh etcOOONCSR 1 + R 2NH 2DMSO/H 2 OMWI, 120 o C, 20 minR 1NHNR 2S68R 1 = H, 5-F, 4,5-dimethoxy PhR 2 = Ph, 3-F 3 CPh, 4-F 3 CPh,2-BrPh, ethyl, bytyl etcSome Russian workers 60 have developed a fast and convenient microwave assistedprocedure for the rapid generation of 7-aryl-2-alkylthio-4,7-dihydro-1,2,4-triazolo[1,5-a]-pyrimidine-6-carboxamides 69 by three-component condensation of 3-amino-2-alkylthio-1,2,4-triazoles with aromatic aldehydes and acetoacetamides. All reactions werecompleted within 5 min of microwave irradition at 120°C and provided the desiredproducts in high yields and excellent purity. Total 60 compounds have been reported.303