1- Aroyl-3- thioureas

Koch, K. R. New chemistry with old ligands N-alkyl- and N,N-dialkyl-N -acyl(aroyl)thioureas in co-ordination, analytical and process chemistry of the platinum group metals. Coord. Chem. Rev. 2001, 216, 473 188. 

Subsequently, by reaction with amine (Eq. 59), N-aryl and N -aroyl thioureas were prepared in excellent yields (86-98%) using this two-step procedure. 

A preparation of the thiazine ring system which should be investigated for generality is that of Baranova et al.,2il who interacted the l-aroyl-2-thioureas 151 with carbon suboxide to give 152. Compounds of structure similar to 152 were also obtained starting with 1,1-disub-stituted thioureas.247 Treatment of other cumulenes 153, ketenes(X = O)... 

Also, reactions of thiourea with /V-heteroarylhydrazonoyl halides were also reported to give different products depending on the nature of the APheteroaryl moiety. For example, while C-aroyl-AL(2-benzimidazolyl)-hydrazonoyl halide 21a reacted with thiourea to give the expected 2-amino-... 

Members of a series of l-aroyl-3-[l-(benzyl-4-piperidinyl)ethyl]thiourea derivatives (269) are potent (submicromolar range) acetylcholinesterase inhibitors (339). 

Thienopyrimidinethiones 85 isomeric to thiones 80 were synthesized by cyclization of thioureas 86 prepared from the corresponding amino(aroyl)thiophenes... 

Scheme 64), microwave irradiation at 50 °C (01JCC73) and, in the case of benzoyl isothiocyanates 240o,p heating in DMF (02PCJ77). The (3-oxopyrazol-4-yl)thioureas 241a-l and the l-aroyl-3-(3-oxopyrazol-4-yl)thioureas were obtained in yields ranging from 56% to 90%. 

The reactions of 2-aminobenzimidazoles have been reviewed <83S86l>. The compounds form Schiffs bases with carbonyl compounds, with isocyanates and isothiocyanates they give ureas and thioureas, they are subject to 1,3-dipolar addition reactions, and to the formation of carbamates on acylation and aroylation. When aminoimidazoles are acylated there is frequently competition between the annular and exocyclic nitrogen (see above). Add chlorides and anhydrides (soft) acylate the amino group chlorocarbonic acid esters (hard) are specific for the heteroatom <84CHE204>. When heated, the A -acyl products isomerize (Scheme 91). 

Under the same reaction conditions, or with various oxidizing reagents, l-aroyl-3-(benzothiazol-2-yl)thioureas (207) undergo cyclization to give 2-aroylimino-2/f-[l,2,4]thiadiazolo[3,2-6]benzo-thiazole (208) (Equation (51)) <90UC(B)778>. 

A -Aroyl-A -substituted thiourea derivatives have been prepared from reaction of aroyl isothiocyanate with amines under solid-liquid phase transfer catalysis condition using polyethylene glycol-400 (PEG-400) as catalyst. Reaction of isothiocyanates with lithiated chiral secondary amines has provided chiral thioureas (Scheme 40). °... 

A very simple, but quite efficient, one-step synthesis of A-aryl-thioureas from primary aromatic amines and ammonium thiocyanate has been reported. Activated isothiocyanates, such as methoxycarbonyl isothiocyanate (1) and acyl or aroyl isothiocyanates, have been applied in the preparation of the JV-heteroaryl-thioureas (2) and (3), or acyl-thioureas (4). Chloroacetyl isothiocyanate... 

---