With triethylamine

To illustrate the specific operations involved, the scheme below shows the first steps and the final detachment reaction of a peptide synthesis starting from the carboxyl terminal. N-Boc-glycine is attached to chloromethylated styrene-divinylbenzene copolymer resin. This polymer swells in organic solvents but is completely insoluble. ) Treatment with HCl in acetic acid removes the fert-butoxycarbonyl (Boc) group as isobutene and carbon dioxide. The resulting amine hydrochloride is neutralized with triethylamine in DMF. 

Chlorosulfonyl isocyanate has been used to introduce 3-carboxamide groups. The initial product, an A -chlorosulfonylcarboxamide, is treated with tri-n-butylstannanc to form the primary carboxamide[15], 3-Cyano groups can also be introduced using chlorosulfonyl isocyanate. The intermediate N-chlorosulfonylindole-3-carboxamide is converted to 3-cyanoindole on reaction with triethylamine[16] or DMF[17],... 

The acylation yields are reported to be improved by conducting the reaction in tetrahydrofuran with triethylamine as catalyst (252-254). 

Several examples of the nucleophilic reactivity of the C-4 atom are known. 2-Phenyl-5 (4HVthiazolinone (212) has been condensed with various aldehydes or ketones in tetrahydrofuran with triethylamine as a catalyst to give 217 (Scheme 110) (392. 442, 444. 445, 447. 450). Mono... 

Reaction of ethyl iodide with triethylamine [(CH3CH2)3N ] yields a crystalline compound CgH2oNI in high yield This compound is soluble in polar solvents such as water but insoluble in nonpolar ones such as diethyl ether It does not melt below about 200°C Suggest a reasonable structure for this product... 

However, depending on the nature of the initial heterocycle, rearrangements are possible. Alkylation of thiazole to form the thiazolium salt (390) and generation of the ylide (391) with triethylamine in the presence of DMAD gave not (392) but the isomeric product (393) by the rearrangement indicated (76JOC187). Rearrangements of these types are described in Chapters 4.07 and 4.19. 

Hydrazoyl halides are useful reagents for the synthesis of pyrazolines and pyrazoles (80JHC833). The elimination of HX, usually with triethylamine, is now the preferred method for the generation of the nitrilimine (621) in situ. Although in some cases it is not clear if the mechanism involves a nitrilimine (621) (as for example in the Fusco method in which sodium salts of /3-diketones are used), in other reactions it is the most reasonable possibility. For example, the synthesis of pyrazolobenzoxazine (633) from the hydrazoyl halide (631) probably occurs via the nitrilimine (632). Trifluoromethylpyrazoles (634) have been prepared by the reaction of a hydrazoyl halide and an alkynic compound in the presence of triethylamine (82H(19)179). 

In contrast to the usual behavior, replacement of the mesyl group in 2 O mesyl-3-diallylaminodeoxy-a-D-altropyranoside by treatment with triethylamine trihydrofluonde leads to, because of neighboring-group participation, the fluori-nated product with retention of configuration [45] (equation 33)... 

In the reaction of CF Cl3 SCl with triethylamine, the yield of the product (CF Cl3 S)2C=CHN(C2H5)2 decreases with decreasing n [fri] (equation 7) (Table 2). 2,3,4,5-Tetrakis(trifluoromethylthio)pyrrole salts react with sulfenyl chloride or SjjCl2 (x = 1,2) to give N-sulfenylaled pyrroles as well as dipyrrolylsulfane and -disulfene. Pentakis(trifluoroniethylthio)pyrrole is a mild sulfenylating... 

Treatment of A -benzyltnfluoroacetimidoyl chloride with triethylamine in toluene at room temperature leads to in situ generation of trifluoroacetonitrile ben-zylide [4J] (equation 43), which reacts with methyl acrylate to form cycloadducts [43] (equation 44) Although the kinetic ratio of products favors the cis adduct (3 1), thermodynamic equilibration leads to an excess of the trans isomer (7 1). 

Figure 3-14 shows an induction period in the reaction of carbon suboxide (O=C=C=C=0) with triethylamine. This reaction is complex and is not yet... 

Stable sulfenes have been isolated by treating methanesulfonyl chloride, with triethylamine or trimethylamine in acetonitrile solvent at -40°C (165,166). These stable sulfenes undergo 1,2 cycloaddition with enamines to form the expected thietanes (trimethylenesulfones). 

Ketoamides can participate in a variation of the Paal-Knorr condensation to yield 5-alkyl-2-aminofurans. Boyd described the cyclization of 1,4-ketoamides 91 upon exposure to acetic anhydride and perchloric acid to yield imminium salts 92 that furnished aminofurans 93 after treatment with triethylamine. ... 

Although benzoxazolium salts are more acidic than their benzothiazol analogs in position 2, isolation of the corresponding dioxa-diazafulvalenes was unsuccessful (72LA126). Comparable to the 1,3-dithiolium- and 1,3-thiazolium salts, 1,2,4-dithiazolium salts yielded on treatment with triethylamine in acetonitrile at 0°C mixed geometrical isomers of the TTDAF... 

Six-membered heterocycles with one tellurium and two nitrogen atoms in the ring are represented by 2-aroyl derivatives of 1,2,3-telluradiazine and 5,6-benzo-1,2,3-telluradiazine 89. For the synthesis of these compounds, IV-aroylhydrazones of 2-bromotellurenylcyclohexenealdehyde and 2-bromotellurenylbenzaldehyde 90 were used as the starting materials (98ZOK959). Dehydrobromination of the hydrazones 90 occurs on treatment with triethylamine and gives the heterocycles 89 in about 80% yields. 

Formylpyrrole oxidatively adds to [Os3(CO)lo(AN)2] by its formyl group giving rise to product 59 followed by cleavage of the C—H bond of this moiety [86JOM(311)371 90OM6]. The complex 59 easily decomposes to 47 and 48. Species 59 further reacts with triethylamine to yield 60 (97P3775). 

The hydroxy compound 59 has been acetylated (94AJC991), and many glycosides have been protected by acetylation. The 4-thione 209 (85LA1922) and the 3-thiol 210 (83USP4419516) have been alkylated using methyl iodide with potassium hydroxide and chloroacetonitrile with triethylamine respectively. 

However, treatment of 4-chloro-3-nitrocoumarin (81) with 2-mercaptophenol (254) provided the product of displacement of the chlorine atom 263. Treatment of compound 263 with triethylamine gave a mixture from which low yields of 266 and 267 were isolated (92ZOR1489). This fact can be explained by the formation of the o-complex 264. This complex is stabilized by carbonyl group participation and therefore an equilibrium of 263 and 265 can be expected. This is in accordance with the formed products (Scheme 41). A similar situation was described earlier for the reaction of 4,5-dichloropyridazin-6(17/)-one with the disodium salt of 2-mercaptophenol (82JHC1447). 

Similar cyclization of 367 leading to low yields (20%) of benzodithiine 368 was observed with triethylamine in DMSO (Eq. 32) (76ZOR844). On the other hand, coumarin derivative 369 treated with 1,2-ethanedithiole in the presence of triethylamine provided relatively stable spiro compound 370 (Eq. 33) (89ZOR669). 

Compound 432, which can be easily prepared from trinitrochlorobenzene (76), treated with triethylamine in dipolar aprotic solvents provided good yield of the denitrocyclization product 433 (80JCS(P1)2205). Reaction of 2,3,5,6-tetra-chloronitrobenzene (434) with various 1,2-diamines under high pressure provided mixtures of the corresponding open products of the nitro group displacement, e.g. 435, and cyclized products, e.g. 436 (Scheme 69). Compound 436 was formed by denitrocyclization reaction, since compound 435 did not cyclize under the used conditions (94BCJ196, 95BCJ3227). 

Treatment of 460 with triethylamine in DMSO gave 15% of 461. This compound was also obtained from spiro complex 462 formed from 460 by the action of potassium rerr-butoxide (Scheme 73) (74ZOR826, 78ZOR105). 

Trinitrochlorobenzene (76) treated with 1,3-propanedithiole and one equivalent of a base provided compound 479 and its treatment with additional base was reported to provide only small yields of benzodithiepine 480 (74CC672). A more recent work described that good yield (80%) of 480 was obtained by a treatment of 479 with triethylamine in benzene (76ZOR844). Similar treatment of 81 provided first spiro complex 481, which refluxed in acetone in the presence of triethylamine gave good yield of the denitrocyclization product 482 (Scheme 77) (92ZOR1496). 

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