109152-48-9

Upstream product

• 98-88-4 benzoyl chloride 
• 109152-46-7 (+)-(S)-3-methylpiperidine-(+)-mandelate 
• 626-56-2 3-Methylpiperidine 
• 432550-82-8 N-benzoyl-N-ethanoylamino-2-[(S)-1-tert-butyldimethylsilyloxy-2-methylpropyl]quinazolin-4(3H)-one 
• 17305-22-5 (+)-(S)-3-methylpiperidine 
• 54731-09-8 N-tosyl-L-prolyl chloride 

Downstream Products

• 100-47-0 benzonitrile 
• 81155-94-4 (-)-(S)-2-methyl-1,5-dibromopentane 

Relevant academic research and scientific papers

Acylative kinetic resolution of racemic methyl-substituted cyclic alkylamines with 2,5-dioxopyrrolidin-1-yl (: R)-2-phenoxypropanoate

The diastereoselective acylation of a number of racemic methyl-substituted cyclic alkylamines with active esters of 2-phenoxypropanoic acid was studied in detail. The ester of (R)-2-phenoxypropanoic acid and N-hydroxysuccinimide was found to be the most selective agent. The highest stereoselectivity was observed in the kinetic resolution of racemic 2-methylpiperidine in toluene at -40 °C (selectivity factor s = 73) with the predominant formation of (R,R)-amide (93.7% de). To explain the observed stereoselectivity, DFT modelling of the transition states in the reactions of the title acylating agent with 2-methylpiperidine and 2-methylpyrrolidine was performed. The calculated values were in good agreement with experimental data. It has been demonstrated that the acylation proceeds via a concerted mechanism, in which the addition of an amine occurs simultaneously with the elimination of the hydroxysuccinimide fragment. The high stereoselectivity of the (R,R)-amide formation is largely ensured by the lower steric hindrances in the transition states as compared to the formation of (R,S)-amide.

N-tosyl-(S)-prolyl chloride in kinetic resolution of racemic heterocyclic amines

The kinetic resolution of racemic heterocyclic amines via acylation with N-tosyl-(S)-prolyl chloride was systematically investigated. It was established that racemic mixtures of aromatic amines could be resolved with high efficiency, while the acylation of 2- and 3-methylpiperidines occurred with low diastereoselectivity. A method for the preparation of enantiomerically pure (3R)-7,8-difluoro-3-methyl-3,4-dihydro-2H-[1,4]benzoxazine was developed.

Kinetic resolution of amines with enantiopure 3-N,N-diacylaminoquinazolin-4(3H)-ones

The title compounds (DAQs) are chiral when the two N-acyl groups are different because of the absence of rotation around the N-N bond (a chiral axis). Enantiopure DAQs have been obtained by incorporation of a chiral centre in enantiopure form either into the substituent at the Q2-position or into one of the N-acyl groups, or into both, followed by separation of diastereoisomers. This separation is unnecessary in one case because conversion of the N-monoacylaminoquinazolinone (MAQ) into the DAQ is completely diastereoselective. Neither is separation of diastereoisomers necessary with 3-[N,N-di-(S)-2-acetoxypropanoylamino]-2-diphenylmethylquinazolin-4(3H)-one 37a: this DAQ 37a has its N-N bond rendered a chiral axis by the bias in its imide moiety wholly in favour of one exo/endo conformation. The high chemoselectivity exhibited by N,N-diacetyl- or N,N-dibenzoylaminoquinazolinones in reaction with the less hindered of two secondary amines (pyrrolidine in the presence of 1 eq. of piperidine) has a stereoselective counterpart: reaction of the above enantiopure DAQs enantioselectively with racemic amines leading to kinetic resolution. Using 1 eq. of DAQ and 2 eq. of amine, both the derivatised and unreacted amine enantiomers are recovered with high enantiomeric excess (ee) (better than 90% ee in some cases). Some of the higher ees are found in the recovered amides where non-chemoselective attack on both N-acyl groups of the DAQ has occurred: from the opposite configurations of the amine component in the two amides and from the low enantiopurity of the recovered unreacted amine, reaction of each of the N-acyl groups with complementary enantiomers of the amine is occurring (parallel kinetic resolution). Although higher ees are, in general, obtained using secondary amines, high ees are obtained in some cases using 1-phenylethylamine and, in particular, amino acid esters (valine and alanine). The sense of enantioselectivity in the reactions of these DAQs with amines is controlled by the configuration of the N-N axis: replacing the Q group in an N-(S)-2-acetoxypropanoyl-N-acetyl-bearing DAQ by phthalimide, thus eliminating the N-N chiral axis, drastically reduces the level of kinetic resolution.

5-(heterocyclic alkyl)-6-aryl-dihydropyrimidines

This invention is directed to dihydropyrimidine compounds of the following formula: which are selective antagonists for human α1Creceptors. This invention is also related to uses of these compounds for lowering intraocular pressure, inhibiting cholesterol synthesis, relaxing lower urinary tract tissue, the treatment of benign prostatic hyperplasia, impotence, cardiac arrhythmia and for the treatment of any disease where antagonism of the α1Creceptor may be useful. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of the above-defined compounds and a pharmaceutically acceptable carrier.

5-(heterocyclic alkyl)-6-aryl-dihydropyrimidines

This invention is directed to dihydropyrimidine compounds of the following formula: which are selective antagonists for human α1Areceptors. This invention is also related to uses of these compounds for lowering intraocular pressure, inhibiting cholesterol synthesis, relaxing lower urinary tract tissue, the treatment of benign prostatic hyperplasia, impotency, cardiac arrhythmia and for the treatment of any disease where antagonism of the α1Areceptor may be useful. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of the above-defined compounds and a pharmaceutically acceptable carrier.