Guanidine groups

Villsmeier reaction on the dimethylacetal of methoxyacetaldehyde (141) with phosgene and dimethyIformamide affords the acrolein derivative, 142. Condensation of this with guanidine gives the pyrimidine, 143. (The enamine can be viewed as a latent aldehyde-the dimethylamino group is probably lost in the course of an addition elimination reaction with one of the guanidine groups.) This pyrimidine serves as starting material for sulfameter (111). ... 

Bicychc pyrazinones foimd in several natural products were synthesized via Michael addition of heterocyclic amines to nitro olefin followed by reduction/cyclization of the nitro group of the adduct [20] (Scheme 5). Further elaboration of the C-6 methoxycarbonyl group in pyrazinone to the n-propyl guanidine group could result in the synthesis of indoloperamine. 

Fig. 6.22 A function model of the sodium channel. P denotes protein, S the potential sensitive sensor and H the gate. The negative sign marks the carboxylate group where the guanidine group of tetro-dotoxin can be attached. (According to B. Hille)...

Argl57 (150), 02 and 03 atoms of the sugar of SAM form hydrogen bonds with the guanidine group of arginine ... 

The association of a specific pharmacologic activity with certain functionality was remarked on earlier. The guanidine group, for exan le, often yields compounds that show hypotensive activity because of peripheral sympathetic blockade (see, for example, bethanidine). Attachment of a piperidine group to the side chain proves compatible with retention of this activity. 

Compounds containing guanidine group arginine, creatinine, bethanidine, streptomycin, phenformin, metformin, chlorhexidine. 

However in the dpg/dpg+ systems, the influenee of hydrogen bonds between the guanidine group and other moleeules is not the sole faetor influencing aromaticity, since the interaction between the guanidinium delocalized t -orbitals and the ring ti-orbitals is also very important. 

The guanidine group is a common structural feature in Nature, primarily due to its ability to stabilize the three-dimensional structure of proteins in enzymes through binding with anionic substrates. Roush and Walts (274) prepared the... 

The key starting material of one of the first antagonists, argatroban (30-6), comprises a derivative of arginine itself in which the amine is protected as its tert-butoxycarbonyl derivative and an A-nitro group moderates the basic nature of the guanidine group (30-2). That intermediate is first condensed with the piperidine... 

Reagent 8 has also been used to add guanidine groups to a supported dipeptide intermediate to a diketopiperazine4 1 that is reported to be a catalyst for enantioselective Strecker reactions.44 The key step is shown in Scheme 19. 

The commercially important representatives of group 4 are diphenyl guanidine and diortho tolyl guanidine. Group 5 includes a number of aldehyde aniline reaction products such as formaldehyde aniline, ethyledene aniline, butraldehyde aniline, heptaldehyde aniline hexa methylenetetraamine and acet-aldehydeaniline. Aetaldehyde, butraldehyde and heptaldehyde derivatives of aromatic amines are powerful accelerators. 

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