1-(2-Imidazolin-2-yl)-2-imidazolines. I. Structure of Jaffe's base and the chemistry of related compounds

Abstract

The synthesis of four potential starting materials for the preparation of 2-amino-1-(2-imidazoliti-2-yl^-imidazolines is described. Treatment of 2-(methylthio)-2-imidazoline (6) with 2-(methylthio)-2-imidazoline hydriodide (7) gave 1-(2-imidazolin-2-yl )-2-(methylthio )-2-imidazoline hydriodide (9) and 1-(2-imidazolin-2-yl )-2-(methylthio)-2-imidazoline hydriodide methanethiol (8). Two minor products, l-( 2-imidazolin-2-yl)-2-[2-(methylthio)-2-imidazolin-l-yl]-2-imidazoiine hydriodide (10) and 2,3,8,9-tetrahydro-5-(methylthio)-7# -imidazo[2,3-fe] [l,3,5]triazepine hydriodide (11), were also obtained. Reaction of 2-(methylthio)-2-imidazoline hydriodide (7) with triethylamine afforded triethyl [l-(2-imidazolin-2-yl)-2-imidazolin-2-yl] ammonium iodide hydriodide methanethiol ( 12) and 1-(2-imidazolin-2-yl)-2-(methylthio)-2-imidazoline dihydriodide methanethiol (13). The determination of the structures of the aforementioned compounds and their relationship to Jaffé's base, 1-(2-imidazolin-2-yl )-2-imidazolidinethione (5), is described. A novel hydrolysis, the transformation of 1-(2-imidazolin-2-yi)-2-(methylthio)-2-imidazoline dihydriodide methanethiol (13) to 8,8-dimethyl dithiocarbonate ( 17) and 2-[(2-aminoethyl)amino]-2-imidazoline dihydroiodide (18), was observed. Evidence which suggests that previously described conversion of 6 to 1-(2-imidazolin-2-yl)-2-imidazolidinone ( 14)1 234 proceeds via alkoxylimidazolinylimidazoline 21 is presented.Structures l1 and 22 initially assigned to Jaffé's base, the product of the interaction of ethylenediamine (3) and thiophosgene (4),1 were subsequently shown to be incorrect; the correct structure 5 was established(1) M. Jaffé and B.

Synthesis of 4-substituted 8-amino-4,5-dihydro-3H-pyrrolo[3,4-f]-1,3,5-triazepin-6-ones and 5-amino-2-aryl-4-(1-aryl-5-alkylideneaminoimidazol-4-yl)1,3-oxazoles

“…One obvious route to these compounds is shown in Scheme 4 and starts from ethyl (Z)-N-(2-amino-1,2dicyanovinyl)formimidate, which is available from the reaction between DAMN and triethyl orthoformate. l 6 The imidate reacts readily at room temperature with acetone and benzaldehyde in the presence of triethylamine to give the compounds 7a and b, respectively, in high yields. In the IR spectra these compounds show a weak cyano stretching vibration at 2200 cm-' in addition to a strong amide carbonyl absorption at 1660 cm-'.…”

Recommended Guanidine Suppressor for the Next-Generation Caustic-Side Solvent Extraction Process

“…Previously published procedures [17,18,19] , and modifications thereof, were followed in the synthesis of the remaining guanidines (see below). All reagents employed in the preparations were used as received from the suppliers without further purification unless otherwise noted.…”