CPC C07D 209/16 (2013.01) [C07D 209/20 (2013.01); C07B 2200/05 (2013.01)] | 19 Claims |
1. A method of synthesising a compound of formula III, or a pharmaceutically acceptable salt thereof,
![]() wherein each xH is independently selected from protium and deuterium, and at least one xH is deuterium,
n is selected from 0, 1, 2, 3 or 4,
R1 is independently selected from —R3, —OR3, —O(CO)R3, —F, —Cl, —Br or —I, and
R2 and R3 are independently selected from C1-C4alkyl,
the method comprising:
reacting a compound of formula I
![]() with two or more coupling agents to produce an activated compound, the two or more coupling agents comprising:
a carbodiimide selected from the group consisting of diisopropylcarbodiimide (DIC), (N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) and 1-cyclohexyl-(2-morpholinoethyl)carbodiimide metho-p-toluene sulfonate (CMCT), and
an additive coupling agent selected from the group consisting of 1-hydroxybenzotriazole, hydroxy-3,4-dihydro-4-oxo-1,2,3-benzotriazine, N-hydroxysuccinimide, 1-hydroxy-7-aza-1H-benzotriazole, ethyl 2-cyano-2-(hydroximino)acetate and 4-(N,N-Dimethylamino)pyridine;
reacting the activated compound with an amine having the formula (R2)2NH to produce a compound of formula II;
![]() reacting the compound of formula II with about 1.8 equivalents of solid LiAlD4 or LiAlH4/LiAlD4 mixture to produce a compound of Formula III; and
optionally reacting the compound of Formula III with an acidic reagent to produce a pharmaceutically acceptable salt of the compound of Formula III.
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