Methylhydrazine → HCID 117678143, compound

Participants

Reaction Steps

To a solution of C28 (100 g, 0.374 mol) in methanol (1.2 L) was added methylhydrazine (40% solution in water, 47.4 g, 0.411 mol). The reaction mixture was heated at reflux for 2 hours, then concentrated to dryness. Purification via silica gel chromatography (Gradient: 5% to 9% ethyl acetate in petroleum ether) provided a mixture of product C49 and tert-butyl 3-cyclopropyl-2-methyl-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (C50). LCMS m/z 278.0 [M+H]+. Separation via supercritical fluid chromatography (Column: Chiral Technologies, Chiralcel OJ-H, 5 um; Eluent: 97:3 carbon dioxide/methanol) afforded the product C49 as the second-eluting isomer, isolated as a solid. NOE studies supported the indicated regiochemical assignment. Yield: 33 g, 120 mmol, 32%. 1H NMR (400 MHz, CDCl3) δ 4.40 (br s, 2H), 3.65-3.73 (br m, 2H), 3.65 (s, 3H), 2.57-2.64 (m, 2H), 1.68-1.76 (m, 1H), 1.49 (s, 9H), 0.77-0.89 (m, 4H).

Provenance & Evidence