Water → Ethyl 7-(benzyloxy)-2,5-dimethylpyrazolo[1,5-a]pyridine-3-carboxylate

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Reaction Steps

11.7 g (28.2 mmol, 1.0 eq.) of 1-amino-2-(benzyloxy)-4-methylpyridinium 2,4,6-trimethylbenzenesulphonate from Example 6A were dissolved in 280 ml of DMF, and 6.6 ml (56 mmol, 2.0 eq.) of ethyl but-2-ynoate [CAS No: 4341-76-8] were added. 7.8 g (56 mmol, 2.0 eq.) of potassium carbonate were added and the mixture was stirred at RT for 1 h. Subsequently, 3.9 g (28 mmol, 1 eq.) of potassium carbonate were added and the mixture was stirred at RT for a further 16 h. Then the mixture was poured onto 540 ml of water and stirred briefly, and the precipitated solids were filtered off, washed with 220 ml of water and dried. 3.1 g of the title compound were obtained (34% of theory; 87% purity).

Provenance & Evidence