Acetic Acid → (Rac)-2-chloro-9-cyclopentyl-7-methyl-5,7,8,9-tetrahydro-pyrimido[4,5-b][1,4]diazepin-6-one

Participants

Reaction Steps

A mixture of 1500 mL of ethanol, 25 mL of acetic acid and 35.2 g of the (rac)-3-[(5-amino-2-chloro-pyrimidin-4-yl)-cyclopentyl-amino]-2-methyl-propanoic acid methyl ester (V-1) prepared in the previous step was heated at reflux overnight, and then concentrated under reduced pressure. The residue was taken up in dichloromethane and washed successively with 10% sodium bicarbonate solution, and then water and dried over anhydrous sodium sulfate. The mixture was filtered and then concentrated under reduced pressure to give 31 g of the crude product. Trituration of the residue with ether, provided 20.7 g of (rac)-2-chloro-9-cyclopentyl-7-methyl-5,7,8,9-tetrahydro-pyrimido[4,5-b][1,4]diazepin-6-one (VI-1).

Provenance & Evidence