Sodium Hydroxide → 5',6,6',7-tetrahydro-5H-spiro[benzo[b]thiophene-4,4'-[1,3]thiazin]-2'-amine

Participants

Reaction Conditions

Reaction Steps

2-(6,7-Dihydrobenzo[b]thiophen-4(5H)-ylidene)ethyl carbamimidothioate (13.8 g, 46 mmol) was suspended in concentrated HCl (150 mL) and stirred at 25° C. until all the solid dissolved. The reaction was monitored by LC/MS until no more starting material remained. The mixture was then neutralised with aqueous 2 M NaOH solution and ice whereupon a solid precipitated out. This was filtered off, washed with water and dried in vacuo to yield the title compound as a white solid (10.35 g, 93%). 1H NMR δ (ppm)(CHCl3-d): 7.05 (1H, d, J=5.25 Hz), 6.88 (1H, d, J=5.24 Hz), 4.79 (2H, s), 3.20-3.01 (2H, m), 2.90-2.74 (2H, m), 2.10-1.98 (2H, m), 1.96-1.77 (4H, m). LCMS (Method f) Rt 2.83 (min) m/z 239 (MH+).

Provenance & Evidence