[Synthesis of isothioureas derived from tetrahydroisoquinoline and NOS inhibitory activity]

To get some novel potent compounds with NOS inhibitory activity, a series of new compounds of isothioureas derived from 1,2,3,4-tetrahydroisoquinoline were synthesized.

1,2, 3,4-Tetrahydroisoquinol-2-yl was introduced into the structure of isothioureas, the NOS inhibitory activity of the new compounds synthesized were measured.

Twenty-two isothiourea derivatives of [alkyl(or aryl) imino] (1,2,3,4-tetrahydroisoquinol-2-yl) methyl alkyl thioethers (I) and S-alkyl-1-phenyl-3-[4-(1,2,3,4-tetrahydroisoquinol-2-yl) methane] phenyl isothioureas (II) were synthesized from thioureas by S-alkylation with alkyl halides, and their structures were identified by IR, 1H NMR, MS and elemental analysis. The preliminary biological test showed that the part of type I (1-9 and 1-13) had higher NOS inhibitory activity than that the control aminoguanidine (AG), but the type II had weak ability to inhibit NOS.