Cyclopropylamines

Fonnation of allylic products is characteristic of solvolytic reactions of other cyclopropyl halides and sulfonates. Similarly, diazotization of cyclopropylamine in aqueous solution gives allyl alcohol. The ring opening of a cyclopropyl cation is an electrocyclic process of the 4 + 2 type, where n equals zero. It should therefore be a disrotatory process. There is another facet to the stereochemistry in substituted cyclopropyl systems. Note that for a cri-2,3-dimethylcyclopropyl cation, for example, two different disrotatory modes are possible, leading to conformationally distinct allyl cations ... 

The /-butyl group can be cleaved from a cyclopropylamine upon prolonged heating in acid (H30, reflux, 3-5 days). ... 

Cyclopropanol, 1-amino- (8, 9), hydrochloride (58939-46-1) Cyclopropylamine, 1-ethoxy- (8) Cyclopropanamine, 1-ethoxy-(9), hydrochloride (58939-48-3)... 

Next analyzed was the behavior of the third quadrant amines, propylamine (PrAM) and cyclopropylamine (CprAM). Surprisingly, PrAM not only did not favor the formation of DHQ, but also decreased the conversion rate of Q in comparison to data observed in the absence of amine, suggesting an effective... 

Lactam ring formation is observed in the rhodium-catalyzed ring-opening carbonylation of cyclopropylamine 20 to N-cyclopropylpyrrolidone 21 (Scheme 8) [14]. (Scheme 8)... 

A more complex type of carbonylation occurs when cyclopropylamine is treated with carbon monoxide in the presence of catalytic amounts of the... 

The synthesis of the corresponding naphthyridone scaffold was carried out according to the methods reported by Chu et al. [12] and Sanchez et al. [13]. Namely, the hydrolysis of ethyl 2,6-dichloro-5-fluoronicotinate (3) [14] followed by reaction with thionyl chloride results in the formation of 2,6-dichloro-5-fluoronicotinyl chloride (4). Treatment of this compound with monoethyl malonate in THF under n-butyllithium followed by acidification and decarboxylation gives rise to ethyl 2,6-dichloro-5-fluoronicotinylacetate (5). Reaction of compound 5 with ethyl orthoformate in acetic acid followed by cyclopropylamine results in the formation of 3-cyclopropylamino-2-(2,6-dichloro-5-fluoronicotinyl)acrylate (6), the cyclization reaction of which under NaH/THF gives rise to the required ethyl l-cyclopropyl-6-fluoro-7-chloro-l,4-dihydro-4-oxo-l,8-naphthyridine-3-carboxylate (7), as shown in Scheme 3. 

The synthesis of compound 27 was initiated with the treatment of ke-toester 29, reported by Yoshida et al. [25], with ethyl orthoformate in acetic acid, followed by reaction with (l.R,2S)-2-fluoro-1-cyclopropylamine p-toluenesulfonic acid salt in the presence of triethylamine to yield an enam-inoketoester intermediate, cyclization of which under NaH in dioxane yields the 5-nitroquinolone derivative (30). Reduction of the nitro group of compound 30 followed by acid hydrolysis provides compound 27 via the amino-quinolone derivative (31), according to Scheme 7. 

The 2-phenylcyclobutylamines Structures 14 and 15 have also been prepared (161). In contrast to the cyclopropylamine, however, 15 showed no clinical activity following oral administration of a dose up to 25 mg of the racemic hydrochloride (199). The trimethoxy congener 14 has not been tested. The appropriately ring-substituted tran.s-2-phenylcyclopentyl or cyclohexylamines have not been reported. Based on the apparent lack of activity for 15, as well as the lack of activity for alpha-ethyl phenethylamine derivatives, however, these might be predicted to be inactive. 

Jacob, J. N., and Nichols, D. E. (1982) Isomeric cyclopropyl ring-methylated homologues of trans-2-(2,5-dimethoxy-4-methylphenyl)cyclopropylamine, an hallucinogen analogue. J. Med. Chem., 25 526-530. 

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