1.1 -thiocarbonyldiimidazole

Solubility sol many organic solvents including THF, CH2CI2, toluene. 

Form Supplied in yellow solid 90% pure or 97% pure. 

Preparative Methods prepared by the reaction of Thiophosgene with 2 equiv of Imidazole. 

Purification can be recrystallized from THF to give yellow crystals can also be sublimed. 

Handling, Storage, and Precautions very hygroscopic should be reacted and stored in a dry atmosphere. 

---

Table 2-1. Various carboxylic acid imidazolides prepared by the use of AyV -carbonyldiimid-azole (CDI), V /V -thiocarbonyldiimidazole (Im-CS-Im) and A -sulfinyldiimidazole (Im-SO-Im).

Table 2-1 lists some examples of carboxylic acid imidazolides of various structures prepared by the use of A -carbonyldiimidazole (CDI), A -thiocarbonyldiimidazole (Im-CS-Im), and A -sulfinyldiimidazole (Im-SO-Im). Independent of the specific method applied, the data in Table 2-1 show that reasonable yields of imidazolides and diimidazolides are quite general, irrespective of various substituents and of steric factors. The rather mild reaction conditions also permit the formation of imidazolides of highly unsaturated systems. As a further advantage, it should be mentioned that almost all imidazolides are crystalline compounds, which can be conveniently handled. Melting points are therefore included for the imidazolides listed in Table 2—1. 

Instead of CDI, analogues like A V -thiocarbonyldiimidazole (ImCSIm), A AT -sulfi-nyldiimidazole (ImSOIm), or A -oxalyldiimidazole (ImCOCOIm) have been used for forming the azoiides. 

TV-Terminal cyclization of peptides by heating to give hydantoins was achieved with CDI or TV,TV -thiocarbonyldiimidazole (ImCSIm) under very mild conditions (room temp.) and without racemization.[55] This method is suitable for determination of the first two amino acids in the sequence of an unknown oligopeptide, as shown in the following two examples ... 

Heterocycles Based on C=0, C=S, or S=0 Insertion Using TVyV -Carbonyldiimidazole (CDI), AyV -Thiocarbonyldiimidazole (ImCSIm), and AyV -Sulfinyldiimidazole (ImSOIm)... 

A l,5,7-triazabicyclo[4.4.0]dec-5-ene containing a bicyclic guanidine system was obtained from a 4,4 -iminobis(butan-2-ylamine) and NJV -thiocarbonyldiimidazole [ 125]... 

For corresponding reactions with 2-furyl- and 2-thienyldiazomethylketone see reference [131]. An obvious mechanism for the reaction of WJV -thiocarbonyldiimidazole with diazomethane is a 1,3-dipolar addition [13°3... 

Analogous to the synthesis of isocyanates, isothiocyanates are obtained in good yield by reacting AyV -thiocarbonyldiimidazole (ImCSIm) with primary aliphatic or aromatic amines in equimolar amount. In chloroform at room temperature the dissociation equilibrium of imidazole-A-thiocarboxamides is shifted completely to isocyanates. 

The reaction of A A -Thiocarbonyldiimidazole (ImCSIm) with (methylidene)-triphenylphosphorane is carried out in analogy to that of CDI.[9]... 

Several examples of the dehydration of acyclic and cyclic hydroxy compounds with CDI, AfN -thiocarbonyldiimidazole, and A -sulfmyldiimidazole, are shown below. 

An azide group can be transformed into a thiocyanate group by reduction with LiAlH4 followed by treatment with NJSl -thiocarbonyldiimidazole.[ 14]... 

Reaction of carbohydrazonamides 143 with l,l -thiocarbonyldiimidazole as the donor of the remaining carbon atom required in tetrahydrofuran gave the corresponding l,2,4-triazol-5-thiones 144, subsequent reaction of which with electrophiles gave 3-alkylthio-l,2,4-triazoles 145a-d in reasonable overall yield (Scheme 12) (Table 28) <2006BMC2507>. 

Table 28 Reaction of carbohydrazonamides with 1,1 -thiocarbonyldiimidazole (Scheme 12)... 

The cyclizations to obtain cyclic thioureas have been performed using thiocarbonyldiimidazole.232 Reaction of methyl acetoacetate, thiourea and an aliphatic aldehyde in the presence of the zinc iodide (Znl2) was studied. Under the normal pressure, reaction has not been occurred whereas at high pressure (300 MPa) conditions 3,4-dihydropyrimidine-2-thione was obtained only in 10% yield.233 The same one-pot three-component cyclocondensation reaction in the presence of iodide (I2) provides a variety of 3,4-dihydropyrimi-dine-2-thione in high yields.234 Condensation reaction of thioureas with a,p-unsaturated ketones in the presence of the sodium methoxide in methanol affords 3,4-dihydropyrimidine-2-thione derivatives.235,236 Acylation of N,N -disubstituted thioureas with methyl malonyl chloride followed by base-catalysed cyclization leads in the formation of l,3-disubstituted-2-thiobarbituric acids (Scheme 78).237... 

Transformation of diols to the corresponding olefins by sequential treatment with l,r-thiocarbonyldiimidazole and trimethylphosphite. Also known as Corey-Winter reductive elimination, or Corey-Winter reductive olefmation. 

Thenoines with urea in acetic acid give 4,5-bis(2,5-dimethyl-3-thienyl)-lH,3H-imidazol-2-one 239, whose treatment with acid chlorides affords photochromes 240 in good yields (02IZV1588). Thenoine 213 with an excess of l,l -carbonyldiimidazole produces l,3-dioxol-2-ones 241 in high yields (02IZV1588). However, thenoine with l,l -thiocarbonyldiimidazole gives 4,5-bis (2,5-dimethyl-3-thienyl)-l,3-oxathiol-2-one 242 instead of the expected thione (04ZOR1743) (Scheme 69). 

Oxo-l,2,4-thiadiazoles were prepared from the corresponding amidoximes and 1,1 -thiocarbonyldiimidazole/BF3 OEt2 or ClSCOCl/EtsN. Thus, amidoximes 278 and ClSCOCl in the presence of EtsN afforded 1,2,4-thiadiazoles 279 in yields up to 20% (equation 120). 

Attempts to functionalize the homoallylic alcohol 15 quickly revealed that this product of an intramolecular aldol condensation was sensitive to base. Fortunately, heating with thiocarbonyldiimidazole effected clean dehydration to give predominantly the desired regioisomer of the diene. Methanolysis followed by oxidation then gave the triketone 1, which on epoxidation with MCPBA gave 2 as the minor component of a 3 1 mixture. 

An impressive solid-phase synthesis of bicyclic guanidines has been communicated, and the approach is outlined in Scheme 20 45,46 iV-acylated dipeptides 18 were reduced to triamines by exhaustive borane reduction, then reacted with thiocarbonyldiimidazole. An intermediate thiocarbonyl was cyclized to the guanidine product in this process. 

First to be explored was xanthate formation. However, this thrust was doomed to failure because of the sensitivity of 107 to base, a likely result of its vinylogous aldol character. Subsequently, it was determined that the desired dehydration could be accomplished simply by heating 107 with thiocarbonyldiimidazole in 1,2-dichlorobenzene.60 This process gave rise to the desired 108 (37% isolated) along with the A2,3 isomer (10%), from which it could be readily separated chromatographically. Hydrolytic removal of the cyclic carbonate in 108 required 3 h to proceed to completion when... 

---