Hydrochloric Acid → 5-(3,3-Dimethyl-but-1-ynyl)-3-[(4-methyl-cyclohex-3-enecarbonyl)-(4-oxo-cyclohexyl)-amino]-thiophene-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

5-(3,3-Dimethyl-but-1-ynyl)-3-[(1,4-dioxa-spiro[4.5]dec-8-yl)-(4-methyl-cyclohex-3-enecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester (240 mg, 0.48 mmol) was dissolved in THF (3.2 mL) and treated with 4M HCl (1.6 mL, 0.8 mmol). The reaction mixture was heated to 45° C. and stirred at ambient temperature. After 2 h, methanol was added (15-20 drops) and the solution was stirred for 3 h. An additional portion of 4M HCl (1.6 mL, 0.8 mmol) and methanol (1 mL) were added and the solution was stirred 16 h at ambient temperature followed by 40° C. for 4 h. The solution was partitioned between water and ethyl acetate. The organic layer was washed with sodium bicarbonate (sat. aq.) and brine, dried over sodium sulfate and concentrated to 233 mg (quantitative yield) of the desired 5-(3,3-dimethyl-but-1-ynyl)-3-[(4-methyl-cyclohex-3-enecarbonyl)-(4-oxo-cyclohexyl)-amino]-thiophene-2-carboxylic acid methyl ester as a white foam.

Provenance & Evidence