Methyl iodide → 2-Chloro-9-cyclopentyl-5,7,7-trimethyl-5,7,8,9-tetrahydro-pyrimido[4,5-b][1,4]diazepin-6-one

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Reaction Steps

To a stirred solution of 10-chloro-2-cyclopentyl-4,4-dimethyl-2,6,9,11-tetrazabicyclo[5.4.0]undeca-8,10,12-trien-5-one (Intermediate 127; 9.67 g, 32.8 mmol) in DMA (710 mL) under nitrogen was added methyl iodide (2.25 mL, 36.08 mmol). The mixture was cooled in ice/water to 2.5° C. Sodium hydride (60% dispersion in mineral oil, 1.45 g, 36.08 mmol) was added in one portion. A small exotherm to 4° C. was observed. The reaction mixture was stirred on an ice/water bath for 1 hour, and then stirred at room temperature overnight. Solvent was removed in vacuo and the light-brown liquid residue was treated with water. This afforded a solid, which was filtered off and washed with water. The solid material was dissolved in DCM (200 mL) and the solution dried using MgSO4, filtered and evaporated to give an off white solid which was purified on a 330 g Si column (Companion). loading as a solution in DCM (60 mL) The column having been equilibrated with 30% Ethyl Acetate in isohexane, and eluted with 30% Ethyl Acetate in isohexane for the first 5 minutes and then with a linear gradient slowly rising to 100% Ethyl Acetate. Product containing fractions were combined and evaporated to dryness to give the title compound as a white solid (9.29 g, 92%)

Provenance & Evidence