204770-99-0

Upstream product

• 204513-00-8 (S)-2-(4-Methoxy-benzyl)-4-methyl-1,2-dihydro-2,4a,9-triaza-anthracene-3,10-dione 
• 300766-81-8 (1S,4S)-2-(2'',4''-dimethoxybenzyl)-1-(3'-indolylmethyl)-4-methyl-2,3,4,6-tetrahydro-1H-pyrazino[2,1-b]quinazoline-3,6-dione 

Downstream Products

• 870674-07-0 (+)-(1R,4S)-1-(2-bromomethyl-3,6-dimethoxybenzyl)-3-ethoxy-4-methyl-1,4-dihydropyrazino[2,1-b]quinazolin-6-one 

Relevant academic research and scientific papers

Synthesis of a seco analogue of ardeemin

(1S,4S)-1-Indolylmethyl-4-methyl-2,4-dihydro-1H-pyrazino[2,1-b]-q uinazaline-3,6-dione, a seco analogue of ardeemin, was synthesized in six steps from L-tryptophan methyl ester via an N-protected 2,5-piperazinedione and using an aza-Wittig reaction for the preparation of the quinazoline system. The final acid-promoted deprotection required tuning of the reaction conditions in order to minimize a side reaction involving loss of the indolylmethyl side chain.

New findings in the alkylation and N-deprotection of (4S)-4-methyl-2- benzyl-2,4-dihydro-1H-pyrazino [2,1-b] quinazoline-3,6-diones

Alkyl halides behave differently to benzyl halides in C-1 alkylation of the title compounds. The syn and anti 1,4-disubstituted diastereomers thus obtained show different regioselectivity by further alkylation leading to the 1,4,4-and 1,1,4-trisubstituted compounds, respectively. Alkylation is always directed anti with respect to the bulkier substituent at C-l or C-4. Debenzylation attempts on 2-benzyl-derivatives lb by treatment with HCOOH and C/Pd or H2/C-Pd/MeOH/H+ led to C-1 oxidised or 7,8,9,10-tetrahydro- derivatives. Deprotection of 2-p-methoxybenzyland 2-(2,4-dimethoxybenzyl)- derivatives with CAN and with TFA/anisole, respectively, was successful, but in the latter case epimerization at C-1 occurred.