Acetic Acid → 1H-Pyrazolo(3,4-d)pyrimidine

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Reaction Steps

Analogously to Example 32, 521 mg (2.00 mmol) of 3-amino-4-(3-chlorophenylamino)-1H-pyrazolo[3,4-d]pyrimidine (see Step 1.6) and 343 μl of acetic acid are dissolved in 50 ml of methanol and reacted with 567 mg (3.0 mmol) of 4-(thiazol-2-yl)-benzaldehyde to form 4-(3chloro-phenylamino)-3t{4-(thiazol-2-yl)-phen-1-yl)methyleneamino]-1H-pyrazolo[3,4-d]pyrimidine. The above intermediate is reduced in 30 ml of DMEU with 16 ml (16 mmol) of DIBAL-H and worked up analogously. The crude product is dissolved in THF/methanol; 20 g of silica gel are added and the mixture is dried to a powder. Application to a silica gel column and elution with CH2Cl2/methanol/H2O/acetic acid (85:13:1.5:0.5) yield 4-(3-chloro-phenylamino)-3-[4-(thiazol-2-yl)-benzylamino]-1H-pyrazolo[3,4-d]pyrimidine; m.p. 241-243° C.; TLC: Rf=0.44 (CHCl3/methanol/H2O/acetic acid=85:13:1.5:0.5); HPLC: tRet(grad20-100)=9.0; FAB-MS: (M+H)+=434.

Provenance & Evidence