Ring Cleavage of N-Acyl- and N-(Arylsulfonyl)histamines with Di-tert-butyl Dicarbonate. A One-Pot Synthesis of 4-Acylamino- and 4-Arylsulfonylamino-1,2-diaminobutanes

The ring cleavage of N-acyl- and N-(arylsulfonyl) histamines with di-tert-butyl dicarbonate in aqueous acetonitrile containing KOAc provides a one-pot synthesis of 4-acylamino- or 4-arylsulfonylamino-1,2-bis(tert-butoxycarbonylamino) butanes. Removal of the Boc groups in these protected triamines with trifluoroacetic acid or dry HCl in MeOH, followed by alkylation with benzyl bromoacetate, and then hydrogenation leads to N 4 -acyl-1,2,4-butanetriamine-N 1 ,N 1 ,N 2 ,N 2 -tetraacetic acids and the N 4 -arylsulfonyl analogs, respectively