4-Piperidinecarboxylic acid → 1-(4-(5-(5-amino-6-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl)-1-methyl-1H-1,2,4-triazol-3-yl)piperidin-1-yl)-3-hydroxypropan-1-one

Participants

Reaction Steps

In an alternative preparation, the N-Boc-isonipecotic acid may be made in situ as follows: Isonipecotic acid (858 g, 3.74 mol) was dissolved in DMA (25.3 L) and 4-methylmorpholine (393 mL, 3.74 mol) added. Stirred for 5 mins and isobutyl chloroformate (489 mL, 3.74 mol) added. The reaction mixture was stirred at 25° C. for 2 h and cooled to 15° C. before (Z)-5-amino-6-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazine-2-carbohydrazonamide (940 g, 3.4 mol) was added portionwise over 10 mins. The reaction mixture was stirred for 1-2 h at 15° C. Water (20.5 L) was added portionwise over 1 h and stirred for a further 1 h before being filtered. The filtercake was then washed with water (4×4 L) and pulled dry on the filter before being dried in a vacuum oven at 50° C. until dry to give the desired product.

Provenance & Evidence