Ethoxycarbonyl isocyanates

Ethoxycarbonyl isocyanate [19617-43-7] M 115.1, Fractionally distilled. [J Heterocycl Chem 5 837 7965.]... 

A Wittig-type reaction of iminophosphorane 995 with benzoyl and ethoxycarbonyl isocyanates gave (91T6747) thiadiazolotriazines 996, whereas reaction of 995 with aromatic isocyanates afforded 997. On the other hand, iminophosphorane 995 reacted with methyl and benzyl isothiocyanates to give 998. Reaction of 995 with acid chlorides gave 999 (88H1935). All these compounds display mesoionic or zwitter ionic character (Scheme 184). 

Reaction of iminophosphorane 1006 with ethoxycarbonyl isocyanate gave (91T6747) regioselectively thiadiazolotriazine derivatives 1007, whereas treatment of 1006 with aromatic isocyanates in ethanol or in the presence of tetrafluoroboric acid afforded 1008 and 1009, respectively. Similarly, 1006 with methyl isocyanate gave 1010 (91T6747) (Scheme 187). 

Arylazo-4-(3-ethoxycarbonylureido)furoxans 62, which were synthesized by the reactions of 4-amino-3-arylazo-furoxans with ethoxycarbonyl isocyanate, were subjected to cascade rearrangements under the action of potassium r/-butoxidc in dimethylformamide or by heating in dimethyl sulfoxide to form 4-amino-2-aryl-5-nitro-2//-l,2,3-triazoles 63 (Scheme 13) <2001MC230, 2003RCB1829>. 

This reactivity enables t/tro-substitution to be carried out at a specific position in the ring, irrespective of the presence of other contra-directing groups, and it allows the reaction to be carried out under mild conditions, or with weak electrophiles such as diazonium ions.2 Recent additions to the extensive list of electrophiles that have been used are toluene />-sulfonylisocyanate and ethoxycarbonyl isocyanate (Equation (53)),176 sulfonyl chloride,177 arene178 and silane sulfonyl chlorides,179 and dichloromethyl methyl ether (Equation (54)).1... 

Singh and Lai [73IJC959 76IJC(B)685] prepared 8,9,10,11-tetrahydro-benzothiazolo[3,2-c]quinazolin-7-ium perchlorate (287) by dehydrative cyclization of 4-[(2-oxocyclohexyl)thio]quinazoline (286) with sulfuric acid and then perchloric acid. 2-(2-Azidophenyl)benzothiazole (288) reacted with triphenylphosphine to give the iminophosphorane, which cyclized to 289 on treatment with ethoxycarbonyl isocyanate (89T4263). 

Thiophene can react with isocyanates or isothiocyanates the products are amides or thioamides respectively. Thus with ethoxycarbonyl isocyanate or isothiocyanate the products... 

A number of penicillin sulfoxides 1 were heated in THF with two equivalents of ethoxycarbonyl isocyanate in the expectation that the corresponding sulfilimines would be obtained. The products, however, were shown to be the imidazo[5,l-c][l,4]thiazines 2, which were obtained in 31-54% yield. 

When the thiazine ester (708) was treated with an isocyanate such as (709), an imidazo[5,l-c][l,4]thiazine (710) was produced (8UAP8161384). Treatment of certain penicillin sulfoxide esters (711) with ethoxycarbonyl isocyanate results in a ring expansion of both rings to afford an imidazo[5,l-c][l,4]thiazine (712) (81JOC3026). 

The synthetically useful ethoxycarbonyl isocyanate reacts with 2-benzimid-azolylacetonitrile or its corresponding acetate ester. Alkyl isocyanates also cyclize the benzimidazol-2-acetate ester [3S70,3S88]. Acyliso(thio)cyanates and a mild base convert 2-methylindolenines (3//-indoles) to a fused pyrimidinedione ring [2695],... 

Pyrimido[4,5-f/Jpyrimidine-2,4,5,7-LeLrol (4) is obtained when 6-aminouracil is treated with ethoxycarbonyl isocyanate followed by thermal cyclization of the intermediate 6-amino-5-[iV-(ethoxycarbonyl)carboxamido]uracil (3).144... 

Using 1-amino-6,7-dimethoxy-3,4-dihydroisoquinoline and ethoxycarbonyl isocyanate, the... 

Amino-2-oxazolines react with ethoxycarbonyl isocyanate to yield oxazolo[3,2-n]-... 

Masquelin et al. have also reported the production of pyrazolo[l,5-a][l,3,5]triazines and pyrozolo[l,5-(j][l,3 5]triazm-4-ones from polymer-bound 3//-pyrozolo[l,5-a][l,3,5] triazin-4-one intermediates 38 (Scheme 12.10). Resin 38 was prepared by condensing4,5-disubstituted 2//-pyrazol-3-ylamine with ethoxycarbonyl isocyanate in dry acetone followed by treatment with sodium ethanolate in ethanol at 65°C and finally attaching onto the Menifield resin. Using such a method, the solid-phase attachment was used to both purify the 3//-pyrazolo[l,5-a][l,3,5]triazin-4-ones via a scavenging process and also introduce a... 

Also, [3+2] cycloadducts are obtained in the reaction of alkyl azides with phenylcarbonyl or ethoxycarbonyl isocyanates . ... 

A -acyl-a-amino-acid (108). 2-Bromo-3-methylthiophen has been carboxylated in the 5-position in high yield, using pyrocatechol dichloromethylene acetal. After esterification, the bromine was reduced by zinc dust, providing a route to isomer-free 4-bromothiophen-2-carboxylic acid. In the presence of stannic chloride, thiophen reacts with ethoxycarbonyl isocyanate or isothiocyanate to give iV-ethoxycarbonylthiophen-2-carboxamide and JV-ethoxycarbonylthiophen-2-thiocarboxamide, respectively. ... 

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