A New One‐step Synthesis of 2,3‐dihydro‐5h‐thiazolo[2,3‐b]quinazolin‐5‐one and 3,4‐dihydro‐2h,6h[1,3]thiazino[2,3‐b] Quinazolin‐6‐one

2,3‐Dihydro‐5 H ‐thiazolo[2,3‐ b ]quinazolin‐5‐one and 3,4‐dihydro‐2 H ,6 H [1,3] thiazino[2,3‐ b ]‐quinazolin‐6‐one have been synthesized in one step by the reaction of methyl anthranilate with ehloroalkyl isothiocyanates.