ethyl N-cyanoethanimidate

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

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

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

Procedure: A mixture of trans-4-amino-3,4-dihydro-2,2-dimethyl-3-hydroxy-2H-1-benzopyran-6-carbonitrile (15.28 g) and ethyl N-cyanoacetimidate (9.42 g) in pyridine (70 ml) was refluxed under nitrogen atmosphere for 9 hours. The mixture was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (150 ml), washed with 5% hydrochloric acid (100 ml), water (100 ml), and brine (100 ml), successively. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was recrystallized from ethyl acetate to give trans-4-[N-[1-(cyanoimino)ethyl]amino]-3,4-dihydro-2,2-dimethyl-3-hydroxy-2H-1-benzopyran-6-carbonitrile (12.68 g). was refluxed under nitrogen atmosphere for 9 hours concentrated under reduced pressure The residue was dissolved in ethyl acetate (150 ml) washed with 5% hydrochloric acid (100 ml), water (100 ml), and brine (100 ml) The organic layer was dried over anhydrous magnesium sulfate concentrated under reduced pressure The residue was recrystallized from ethyl acetate

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

Procedure: A mixture of trans-4-amino-3,4-dihydro-2,2-dimethyl-3-hydroxy-2H-1-benzopyran-6-carbonitrile (15.28 g) and ethyl N-cyanoacetimidate (9.42 g) in pyridine (70 ml) was refluxed under nitrogen atmosphere for 9 hours. The mixture was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (150 ml), washed with 5% hydrochloric acid (100 ml), water (100 ml), and brine (100 ml), successively. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was recrystallized from ethyl acetate to give trans-4-[N-[1-(cyanoimino)ethyl]amino]-3,4-dihydro-2,2-dimethyl-3-hydroxy-2H-1-benzopyran-6-carbonitrile (12.68 g). was refluxed under nitrogen atmosphere for 9 hours concentrated under reduced pressure The residue was dissolved in ethyl acetate (150 ml) washed with 5% hydrochloric acid (100 ml), water (100 ml), and brine (100 ml) The organic layer was dried over anhydrous magnesium sulfate concentrated under reduced pressure The residue was recrystallized from ethyl acetate

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

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

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

Procedure: To 1.54 g of ethyl N-cyanoacetimidate, 3.86 g of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-benzylamino-2H-benzo[b]pyran-3-ol was added, and the mixture was reacted under stirring at a temperature of from 100° to 120° C. for 2 hours. The reaction mixture was cooled, then dissolved in 100 ml of ethyl acetate, washed twice with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. Then, ethyl acetate was distilled off under reduced pressure. The residual solid was purified by silica gel chromatography to obtain 1.65 g of the above identified compound in the form of crystals. the mixture was reacted The reaction mixture was cooled washed twice with a saturated sodium chloride aqueous solution dried over anhydrous sodium sulfate Then, ethyl acetate was distilled off under reduced pressure The residual solid was purified by silica gel chromatography to obtain 1.65 g of the

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

Procedure: To 1.54 g of ethyl N-cyanoacetimidate, 3.86 g of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-benzylamino-2H-benzo[b]pyran-3-ol was added, and the mixture was reacted under stirring at a temperature of from 100° to 120° C. for 2 hours. The reaction mixture was cooled, then dissolved in 100 ml of ethyl acetate, washed twice with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. Then, ethyl acetate was distilled off under reduced pressure. The residual solid was purified by silica gel chromatography to obtain 1.65 g of the above identified compound in the form of crystals. the mixture was reacted The reaction mixture was cooled washed twice with a saturated sodium chloride aqueous solution dried over anhydrous sodium sulfate Then, ethyl acetate was distilled off under reduced pressure The residual solid was purified by silica gel chromatography to obtain 1.65 g of the

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

Procedure: To 1.54 g of ethyl N-cyanoacetimidate, 3.86 g of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-benzylamino-2H-benzo[b]pyran-3-ol was added, and the mixture was reacted under stirring at a temperature of from 100° to 120° C. for 2 hours. The reaction mixture was cooled, then dissolved in 100 ml of ethyl acetate, washed twice with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. Then, ethyl acetate was distilled off under reduced pressure. The residual solid was purified by silica gel chromatography to obtain 1.65 g of the above identified compound in the form of crystals. the mixture was reacted The reaction mixture was cooled washed twice with a saturated sodium chloride aqueous solution dried over anhydrous sodium sulfate Then, ethyl acetate was distilled off under reduced pressure The residual solid was purified by silica gel chromatography to obtain 1.65 g of the

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

Procedure: To 2.80 g of ethyl N-cyanoacetimidate, 4.65 g of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-methylamino-2H-benzo[b]pyran-3-ol was added, and the mixture was reacted under stirring at a temperature of from 100° to 120° C. for 2 hours. The reaction mixture was cooled, then dissolved in 100 ml of ethyl acetate, washed twice with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. Then, ethyl acetate was distilled off under reduced pressure. The residual solid was recrystallized from ethanol to obtain 2.34 g of the above identified compound in the form of crystals. the mixture was reacted The reaction mixture was cooled washed twice with a saturated sodium chloride aqueous solution dried over anhydrous sodium sulfate Then, ethyl acetate was distilled off under reduced pressure The residual solid was recrystallized from ethanol to obtain 2.34 g of the

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

Procedure: To 1.23 g of ethyl N-cyanoacetimidate, 2.18 g of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-amino-2H-benzo[b]pyran-3-ol was added, and the mixture was stirred at a temperature of from 100° to 120° C. for 2 hours. The reaction mixture was cooled, then dissolved in 100 ml of ethyl acetate, washed twice with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. Then, ethyl acetate was distilled off under reduced pressure. The residual oily substance was recrystallized from ethyl acetate/n-hexane to obtain 1.75 g of the above identified compound in the form of crystals. The reaction mixture was cooled washed twice with a saturated sodium chloride aqueous solution dried over anhydrous sodium sulfate Then, ethyl acetate was distilled off under reduced pressure The residual oily substance was recrystallized from ethyl acetate/n-hexane to obtain 1.75 g of the

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

Procedure: Preparation of N′-cyano-N-(2-(5-(2,5-difluorophenyl)-3-((S-2-methoxypropanoyl)-2-phenyl-2,3-dihydro-1,3,4-thiadiazol-2-yl)ethyl)acetamidine: To a solution of ethyl N-cyanoacetimidate (0.025 g, 0.22 mmol) and (2S)—(2-(2-aminoethyl)-5-(2,5-difluorophenyl)-2-phenyl-1,3,4-thiadiazol-3(2H)-yl)-2-methoxypropan-1-one hydrochloride (0.018 g, 0.038 mmol) in EtOH (0.3 mL) was added diisopropylethylamine (0.033 mL, 0.19 mmol). After stirring at room temperature for 14 hours, the mixture was diluted with 10% Na2CO3 (30 mL) and extracted with dichloromethane. The combined organics were dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed (3% MeOH in dichloromethane) to provide the product as a mixture of diastereomers (13.0 mg, 73% yield). MS ESI (+) m/z 472 (M+1) detected; 1H NMR (400 MHz, CDCl3) δ 7.51 (m, 2H), 7.37 (m, 6H), 7.33 (m, 4H), 7.16 (m, 4H), 6.93 (br. t, 1H, J=4.7 Hz), 6.73 (br. t, 1H, J=4.7 Hz), 4.73 (m, 2H), 4.00 (m, 2H), 3.45-3.29 (m, 9H), 3.21 (m, 1H), 2.82 (m, 1H), 2.75 (m, 1H), 2.16 (s, 3H), 2.15 (s, 3H), 1.46 (d, 3H, J=6.3 Hz), 1.43 (d, 3H, J=7.0 Hz). extracted with dichloromethane The combined organics were dried over Na2SO4 filtered concentrated under reduced pressure The residue was chromatographed (3% MeOH in dichloromethane) to provide the product as a mixture of diastereomers (13.0 mg, 73% yield)