Acetic Acid → HCID 178478149, compound

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Reaction Steps

Analogously to Example 32, 260 mg (1.00 mmol) of 3-amino-4-(3-chlorophenylamino)-1H-pyrazolo[3,4-d]pyrimidine and 172 μl of acetic acid are dissolved in 25 ml of methanol and reacted with 261 mg (1.5 mmol) of 3-(tetrazol-5-yl)-benzaldehyde (Step 59.1) to form 4-(3-chloro-phenylamino)-3-{[3-(tetrazol-5-yl)-phenyl)-methyleneamino}-1H-pyrazolo[3,4-d]pyrimidine. With ice-cooling, 8 ml (8 mmol) of DIBAL-H are added to the above intermediate in 15 ml of DMEU and the reaction mixture is stirred for 30 min. 15 ml of ethyl acetate are added and the mixture is stirred for 15 min, diluted with 150 ml of methanol and 1 ml of water and concentrated by evaporation in a rotary evaporator. The residue is poured into 0.5 liter of water and 0.5 liter of ethyl acetate, and acidified to pH=3 with 1 N HCl, and the aqueous phase is separated off and extracted a further 3× with ethyl acetate. The organic phases are washed several times with water and finally with brine, dried (Na2SO4) and concentrated by evaporation. Stirring in ether yields 4-(3-chloro-phenylamino)-3-[3-(tetrazol-5-yl)-benzylamino-]-1H-pyrazolo[3,4-d]pyrimidine; TLC: Rf=0.13 (CHCl3/methanol/H2O/acetic acid=85:13:1.5:0.5); HPLC: tRet(grad20-100)=7.4; FAB-MS: (M+H)+=419.

Provenance & Evidence