HETEROCYCLIC RING-CLOSURE REACTIONS .2. REACTIONS OF ALPHA-MERCAPTO ACIDS WITH CYANOGEN

The reaction of α-mercapto acids with cyanogen has been studied and shown to give 2-[(S-carboxyalkyl)-thioimidyl]-∆2-thiazolin-4-one in good yields. The reaction product undergoes unusual N-methylation in addition to esterification when treated with diazomethane and could be cyclized to afford bicyclic symmetrical 4,4ʹ-diketo-∆2-bithiazolinyl, which could be converted into its dienol diacetate. Proof of structure has been obtained by X-ray crystallography and supporting evidence obtained from uv, ir, nmr, and pKa determinations and dipole moment measurements. © 1969, American Chemical Society. All rights reserved.