2-Naphthalenethiol → 4-(Naphthalen-2-ylsulfanyl)-5-nitro-thiophene-2-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

To a suspension of NaH (30 mg, 1.24 mmol) in DMF was slowly added dropwise naphthalene-2-thiol (199 mg, 1.24 mmol, Aldrich Chemical Company) in DMF at rt. This clear solution was then added dropwise to a solution of 4-bromo-5-nitro-thiophene-2-carboxylic acid methyl ester ((Example 114, step c) 300 mg, 1.27 mmol) in DMF at rt. Aqueous workup resulted in isolation of 4-(naphthalen-2-ylsulfanyl)-5-nitro-thiophene-2-carboxylic acid methyl ester. The procedure as in Example 20: step b was followed using 4-(naphthalen-2-ylsulfanyl)-5-nitro-thiophene-2-carboxylic acid methyl ester (194 mg, 0.56 mmol) and m-CPBA (354.4 mg, 1.2 mmol) resulting in 4-(naphthalene-2-sulfonyl)-5-nitro-thiophene-2-carboxylic acid methyl ester. The procedure as in Example 27: step a was followed using 4-(naphthalene-2-sulfonyl)-5-nitro-thiophene-2-carboxylic acid methyl ester (32 mg, 0.085 mmol) sodium thiomethoxide (7.55 mg, 0.94 mmol) resulting in 5-methylsulfanyl-4-(naphthalene-2-sulfonyl)-thiophene-2-carboxylic acid methyl ester. The procedure as in Example 20: step f was followed using 5-methylsulfanyl-4-(naphthalene-2-sulfonyl)-thiophene-2-carboxylic acid methyl ester (29 mg, 0.77 mmol) and dimethyl aluminum amide (0.39 mL, 0.39 mmol) resulting in the title compound 5-methylsulfanyl-4-(naphthalene-2-sulfonyl)-thiophene-2-carboxamidine triflouroacetate (19 mg, 70%). 1H-NMR (CD3OD): δ: 8.67 (m, 1H), 8.37 (s, 1H), 8.05–8.15 (m, 2H), 7.95–8.01 (d, J=7.21 Hz, 1H), 7.90–7.95 (d of d, J=6.7, 2.0 Hz), 7.65–7.75 (m, 2H), 2.70 (s, 3H).

Herkunft & Nachweise