3-ethoxycarbonyl-2-methyl-, ring

Of interest is also that the rate of liberation of penicillin G from the prodrug was much faster than the breakdown of the former by opening of its /3-lactam ring. Furthermore, no breakdown of the pro-moiety A-(hydroxy-methyl)-A-[(ethoxycarbonyl)methyl]benzamide (8.58) to liberate formaldehyde was detected over the timescale of ester hydrolysis. 

Aminofuran-2-ones (15) (R = COAr, COMe) could be synthesized by Thorpe-Ziegler cyclization of acylmethyl esters 13 and 14 in the presence of NEt3 and NaOEt, respectively. However, the less acidic ethoxycarbonyl-methyl componds 13 and 14 (R = COOEt) or cyanomethyl esters (R = CN) failed to ring close (84LA1702) (Scheme 4). The starting esters could... 

The 1-ethoxycarbonylmethyl group of 1-(ethoxycarbonyl-methyl )-1-methoxy-2,4,6-triphenylphosphorin is readily hydrolysed to -CH2CO2H, esterified to -CH2C02Me and reduced to -CH2CH2OH without destroying the ring system (Dimroth and Kieselack, Ber., 1975, 108, 3671). 

Extension of the aminopalladation-reductive elimination domino methodology to the conunercially available ethyl iodoacetate provides a new approach to the construction of indole rings containing the 3-(ethoxycarbonyl)methyl group. Employment of the same conditions reported for the preparation of 2,3-disubstituted indolesf and 2-unsubstituted 3-arylindoles fail to give the desired indole derivatives, at least with the model system, the Af-alkyl derivative being the main or sole reaction product (Scheme 22). 

Thiophene, 2-amino-3-cyano-5-phenyl-synthesis, 4, 888-889 Thiophene, 3-amino-4,5-dihydro-cycloaddition reactions, 4, 848 Thiophene, 2-amino-3-ethoxycarbonyl-ring opening, 4, 73 Thiophene, 2-amino-5-methyl-synthesis, 4, 73 Thiophene, 2-anilino-synthesis, 4, 923-924 Thiophene, aryl-synthesis, 4, 836, 914-916 Thiophene, 2-(arylamino)-3-nitro-synthesis, 4, 892 Thiophene, azido-nitrenes, 4, 818-820 reactions, 4, 818-820 thermal fragmentation, 4, 819-820 Thiophene, 3-azido-4-formyl-reactions... 

Methyl 2,7- and 3,6-dimethyl-l//-azepine-1-carboxylate also show marked differences towards acid hydrolysis. The 3,6-dimethyl isomer, with 10% sulfuric acid at 20°C, forms the expected A,-(ethoxycarbonyl)-2,5-dimethylaniline in high yield (82%) however, the 2,7-dimethyl isomer requires more forcing conditions to effect ring contraction and yields a mixture of A-(methoxycarbonyl)-2,6-dimethylaniline (16% mp 103-105°C), A-(methoxycarbonyl)-2,3-dimethylaniline (1% mp 90-92°C), 2,6-dimethylphenol (1%), and 3,4-dimethylphenol (6% mp 66-67 C).115 A mechanistic rationale for these results has been proposed. 

Ethyl 3-azido-l-methyl-177-indole-2-carboxylate 361 is prepared in 70% yield by diazotization of amine 360 followed by substitution of the created diazonium group with sodium azide. In cycloadditions with nitrile anions, azide 361 forms triazole intermediates 362. However, under the reaction conditions, cyclocondensation of the amino and ethoxycarbonyl groups in 362 results in formation of an additional ring. This domino process provides efficiently 4/7-indolo[2,3-i ]l,2,3-triazolo[l,5- ]pyrimidines 363 in 70-80% yield (Scheme 57) <2006TL2187>. 

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... 

Amino-5(4)-ethoxycarbonyl-imidazol wird mit Formaldehyd/Dimethylamin nicht an der Amino-Gruppe, sondern am Ring-C-Atom in 2-Stellung zu 4(5)-Amino-2-(dimethylamino-methyl)-5(4)-ethoxycarbonyl-imidazol 1-amino-alkyliert762. 

---