2-ethoxybenzohydrazide

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl butyrimidate hydrochloride from Example B (71.5 g, 472 mmol) is introduced into triethylamine (65 ml, 472 mmol) and cooled to 0° C. 2-Ethoxybenzohydrazide from Example A (85 g, 472 mmol) is suspended in 250 ml of isopropanol and added to the ethyl butyrimidate mixture. The reaction mixture is stirred at room temperature for 48 hours, the solid (triethylamine hydrochloride) is removed, and 25% strength hydrochloric acid (150 ml, 1.18 mol) is slowly added dropwise to the mother liquor at 0° C. to 5° C. The suspension of crystals is then stirred at 0° C. to 5° C. for 1 hour and the crystals are filtered with suction through a sintered funnel, washed with 100 ml of cold isopropanol and dried in a vacuum oven at 30° C. and 300 mbar overnight. the solid (triethylamine hydrochloride) is removed The suspension of crystals is then stirred at 0° C. to 5° C. for 1 hour the crystals are filtered with suction through a sintered funnel washed with 100 ml of cold isopropanol dried in a vacuum oven at 30° C. 300 mbar overnight

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl 2-ethoxybenzoate (100 g, 128.7 mmol) and hydrazine hydrate (100%, 25 ml, 128.7 mmol) are dissolved in 200 ml of ethanol and heated under reflux for 5 hours. A further 12.5 ml (64.3 mmol) of hydrazine hydrate are added and the reaction mixture is heated under reflux for a further 7 hours. For working up, the reaction mixture is extensively concentrated and then stirred with 300 ml of cyclohexane at room temperature. After cooling to 0° C., the crystals are filtered off with suction, washed twice with 50 ml of cold cyclohexane each time and finally dried in a vacuum oven at 35° C. and 300 mbar overnight. heated under reflux for 5 hours the reaction mixture is heated under reflux for a further 7 hours the reaction mixture is extensively concentrated After cooling to 0° C. the crystals are filtered off with suction washed twice with 50 ml of cold cyclohexane each time finally dried in a vacuum oven at 35° C. 300 mbar overnight

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the carboxylic acid (A1) in DCM was added to PS-CDI (1.7 eq., loading 1.30 mmol/g), and the suspension stirred at RT for 30 min. 2-Ethoxybenzohydrazide (1.3 eq.) dissolved in DCM/DMF was added, and the resulting suspension was stirred at RT overnight. The suspension was filtered and the filtrate evaporated. The crude N′-(2-ethoxybenzoyl)-5-(trifluoroacetyl)thiophene-2-carbohydrazide (MS (ES) C16H13F3N2O4S requires: 386, found: 427 (M+H20+Na)+ and 385 (M−H+e)−) was used as such, without any purification. It was dissolved in excess thionyl chloride and the solution was heated in a microwave oven (sealed tube, 100° C., 5 min) and the thionyl chloride was evaporated. The desired product was isolated by preparative RP-HPLC, using H2O (0.1% TFA) and MeCN (0.1% TFA) as eluents (column: C18). The pooled product fractions were evaporated to afford the title compound. 1H NMR (300 MHz, CD3CN): 8.1-8.08 (1H, m), 8.06-8.01 (1H, m), 7.95-7.90 (1H, m), 7.63-7.56 (1H, m), 7.23-7.17 (1H, m), 7.16-7.09 (1H, m), 4.23 (2H, q, J=7 Hz), 1.48 (3H, t, J=7 Hz). 19F NMR (282 MHz, CD3CN); δ −74.25 (keto form), −86.14 (hydrate form). MS (ES) C16H11F3N2O3S requires: 368, found: 369 (M+H)+ and 387 (M+H2O+H)+. was added the resulting suspension was stirred at RT overnight The suspension was filtered the filtrate evaporated without any purification It was dissolved in excess thionyl chloride the solution was heated in a microwave oven (sealed tube, 100° C., 5 min) the thionyl chloride was evaporated

Conditions: temp:0.00; pressure:0.00; stir: