tert-butyl N-[2-[2-(2-aminoethoxy)ethoxy]ethyl]carbamate

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

Procedure: A solution of vitamin H (Biotin) (2.2 g, 9 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU) (3 g, 8 mmol), and DIPEA (1.8 mL, 10 mmol) in DMF (100 mL) was stirred for 10 minutes at room temperature before being adding dropwise to a solution of N-Boc-3,6-dioxaoctane-1,8-diamine (1.5 g, 6 mmol, 1). The reaction mixture was stirred for 1 hour at room temperature, after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1, v/v) to afford N-Boc-N′-biotinyl-3,6-dioxaoctane-1,8-diamine (2.0 g, 90%). 1H NMR (300 MHz, CD3OD): δ 4.5 (m, 1H), 4.3 (m, 1H), 3.6 (s, 4H), 3.54 (tt, 4H), 3.39 (t, 2H), 3.26 (t, 2H), 2.9 (dd, 1H), 2.7 (d, 1H), 2.2 (t, 2H), 1.7-1.5 (m, 8H), 1.4 (s, 9H); MALDI HRMS: m/z 497.2416 [M+Na+]. Calcd for C21H38N4NaO6S 497.2410. after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1

Conditions: temp:21.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of biotin (0.59 g, 2.42 mmol, 1.5 eq), HBTU (0.79 g, 2.10 mmol, 1.3 eq) and DIEA (0.45 mL, 2.60 mmol, 1.6 eq) in DMF (15 mL) was stirred for 20 min at 21° C. before being added dropwise to a solution of tert-butyl-N-(2-(2-(2-aminoethoxy)ethoxy)ethyl)carbamate (400 mg, 1.61 mmol, 1 eq) in DMF (10 mL). The reaction mixture was stirred for 2 h at 21° C., after which the DMF was removed in vacuo to give a yellow residue. The crude product was purified by column chromatography (gradient 2-10% MeOH/CH2Cl2) to yield the desired compound as a white solid (0.61 g, 1.29 mmol, 80% yield). m.p. 106-108° C.; [α]D20.0+23.0 (c 0.6, CH2Cl2); 1H NMR (500 MHz, CDCl3) δ 4.55 (dd, J=5.0, 7.5 Hz, 1H, NHC(O)NHCH), 4.36 (dd, J=5.0, 7.5 Hz, 1H, NHC(O)NHCH), 3.62 (bs, 6H, OCH2), 3.59-3.55 (m, 2H, OCH2), 3.46 (m, 2H, NCH2), 3.31 (m, 2H, NCH2), 3.17 (dt, 3.0, 5.0 Hz, 1H, SCH), 2.92 (dd, J=5.0, 13.0 Hz, 1H, SCHH), 2.79 (d, J=13.0 Hz, 1H, SCHH), 2.27 (t, J=7.0 Hz, 2H, NHC(O)CH2CH2CH2), 1.71 (m, 4H, NHC(O)CH2CH2CH2CH2), 1.47 (br, 11H, C(CH3)3 & NHC(O)CH2CH2CH2CH2); 13C NMR (125 MHz, CDCl3) δ 173.69 (s), 163.92 (s), 155.99 (s), 79.14 (s), 70.03 (t), 69.69 (br t), 61.58 (d), 60.06 (d), 55.19 (d), 40.16 (t), 39.96 (t), 38.91 (t), 35.44 (t), 28.09 (q), 27.80 (t), 27.67 (t), 25.23 (t), * 2 t absent; IR (neat) 3307, 2933, 1691 cm−; HRMS (ES) calcd for C21H38N4O6NaS [M+Na]+ 497.2410, observed 497.2423. after which the DMF was removed in vacuo to give a yellow residue The crude product was purified by column chromatography (gradient 2-10% MeOH/CH2Cl2)

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

Procedure: A solution of vitamin H (Biotin) (2.2 g, 9 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU) (3 g, 8 mmol), and DIPEA (1.8 mL, 10 mmol) in DMF (100 mL) was stirred for 10 minutes at room temperature before being adding dropwise to a solution of N-Boc-3,6-dioxaoctane-1,8-diamine (1.5 g, 6 mmol, 1). The reaction mixture was stirred for 1 hour at room temperature, after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1, v/v) to afford N-Boc-N′-biotinyl-3,6-dioxaoctane-1,8-diamine (2.0 g, 90%). 1H NMR (300 MHz, CD3OD): δ 4.5 (m, 1H), 4.3 (m, 1H), 3.6 (s, 4H), 3.54 (tt, 4H), 3.39 (t, 2H), 3.26 (t, 2H), 2.9 (dd, 1H), 2.7 (d, 1H), 2.2 (t, 2H), 1.7-1.5 (m, 8H), 1.4 (s, 9H); MALDI HRMS: m/z 497.2416 [M+Na+]. Calcd for C21H38N4NaO6S 497.2410. after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1

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

Procedure: A mixture of 4-[(4-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}piperidin-1-yl)methyl]benzoic acid (1.20 g; 2.63 mmol), TBTU (1.01 g; 3.15 mmol) and DIPEA (1.8 ml; 3.15 mmol) in DMF (10 ml) is stirred for 5 min. tert-Butyl N-{2-[2-(2-aminoethoxy)ethoxy]ethyl}carbamate (783 mg; 3.15 mmol) is added and the mixture is stirred overnight. Volatiles are evaporated and the product is purified by RP-HPLC (modifier: TFA) to yield 9H-fluoren-9-ylmethyl N-(1-{[4-({2-[2-(2-{[(tertbutoxy)carbonyl]amino}ethoxy)ethoxy]ethyl}carbamoyl)phenyl]methyl}piperidin-4-yl)carbamate. is added Volatiles are evaporated the product is purified by RP-HPLC (modifier: TFA)

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

Procedure: Preparation from 1-(t-butyloxycarbonylamino)-3,6-dioxa-8-octanamine) (5 g, 20.16 mmol) and succinic anhydride (2.218 g, 22.18 mmol) gave a thick yellow oil which crystallised on standing (6.5 g, yield 98%). LCMS (Method 6): Rt 2.99 min; m/z (M+1) 349; Calcd.: 349. gave a thick yellow oil which crystallised

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

Procedure: Preparation from 1-(t-butyloxycarbonylamino)-3,6-dioxa-8-octanamine) (5 g, 20.16 mmol) and succinic anhydride (2.218 g, 22.18 mmol) gave a thick yellow oil which crystallised on standing (6.5 g, yield 98%). LCMS (Method 6): Rt 2.99 min; m/z (M+1) 349; Calcd.: 349. gave a thick yellow oil which crystallised

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

Procedure: To (S)-4-(4-((2-amino-4-hydroxypteridin-6-yl)methylamino)benzamido)-5-methoxy-5-oxopentanoic acid (240 mg, 0.53 mmol, crude), triethylamine (0.3 mL, 2.2 mmol), and tert-butyl 2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate (150 mg, 0.60 mmol) in N,N-dimethylformamide (3 mL), 2-(2-pyridon-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (261 mg, 0.88 mmol) was added in one portion. The reaction was stirred at ambient temperature for 16 hours. After this time, the product was crashed out with diethyl ether and collected by suction filtration. The solids were washed with methylene chloride (30 mL) to afford crude (S)-methyl 18-(4-((2-amino-4-hydroxypteridin-6-yl)methylamino)benzamido)-2,2-dimethyl-4,15-dioxo-3,8,11-trioxa-5,14-diazanonadecan-19-oate (225 mg, 62%) as an orange-brown solid, which was used in the next step without further purification: MM-APCI MS m/z=684 [M−H]−. collected by suction filtration The solids were washed with methylene chloride (30 mL)

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

Procedure: By appropriate application of the method used to synthesize Intermediate 5, tert-butyl 2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate (400 mg, 1.6 mmol) and 3-(1,3-dioxoisoindolin-2-yl)propanoic acid (388 mg, 1.8 mmol) were combined to provide Intermediate 7A (700 mg, 87% yield). HPLC/MS (Method C) RT=2.80 min, [M+H]+ 450.

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

Procedure: By appropriate application of the method used to synthesize Intermediate 5, tert-butyl 2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate (400 mg, 1.6 mmol) and 3-(1,3-dioxoisoindolin-2-yl)propanoic acid (388 mg, 1.8 mmol) were combined to provide Intermediate 7A (700 mg, 87% yield). HPLC/MS (Method C) RT=2.80 min, [M+H]+ 450.

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

Procedure: A solution of vitamin H (Biotin) (2.2 g, 9 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU) (3 g, 8 mmol), and DIPEA (1.8 mL, 10 mmol) in DMF (100 mL) was stirred for 10 minutes at room temperature before being adding dropwise to a solution of N-Boc-3,6-dioxaoctane-1,8-diamine (1.5 g, 6 mmol, 1). The reaction mixture was stirred for 1 hour at room temperature, after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1, v/v) to afford N-Boc-N′-biotinyl-3,6-dioxaoctane-1,8-diamine (2.0 g, 90%). 1H NMR (300 MHz, CD3OD): δ 4.5 (m, 1H), 4.3 (m, 1H), 3.6 (s, 4H), 3.54 (tt, 4H), 3.39 (t, 2H), 3.26 (t, 2H), 2.9 (dd, 1H), 2.7 (d, 1H), 2.2 (t, 2H), 1.7-1.5 (m, 8H), 1.4 (s, 9H); MALDI HRMS: m/z 497.2416 [M+Na+]. Calcd for C21H38N4NaO6S 497.2410. after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: DIPEA (142 mg, 1.10 mmol), tert-butyl 2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate (273 mg, 1.10 mmol), and 2 (150 mg, 0.55 mmol) were dissolved in THF (5 mL). The mixture was stirred at 70° C. under N2 overnight. The solvent was removed under reduced pressure. The resulting residue was purified by column chromatography on silica gel (eluent CH3OH/CH2Cl2=2/98) to give 3 as a white solid (124 mg, 47%): ESI-MS m/z 485.2 (M+H+) calculated for C19H37N10O5 485.3. The solvent was removed under reduced pressure The resulting residue was purified by column chromatography on silica gel (eluent CH3OH/CH2Cl2=2/98)

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

Procedure: A solution of vitamin H (Biotin) (2.2 g, 9 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU) (3 g, 8 mmol), and DIPEA (1.8 mL, 10 mmol) in DMF (100 mL) was stirred for 10 minutes at room temperature before being adding dropwise to a solution of N-Boc-3,6-dioxaoctane-1,8-diamine (1.5 g, 6 mmol, 1). The reaction mixture was stirred for 1 hour at room temperature, after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1, v/v) to afford N-Boc-N′-biotinyl-3,6-dioxaoctane-1,8-diamine (2.0 g, 90%). 1H NMR (300 MHz, CD3OD): δ 4.5 (m, 1H), 4.3 (m, 1H), 3.6 (s, 4H), 3.54 (tt, 4H), 3.39 (t, 2H), 3.26 (t, 2H), 2.9 (dd, 1H), 2.7 (d, 1H), 2.2 (t, 2H), 1.7-1.5 (m, 8H), 1.4 (s, 9H); MALDI HRMS: m/z 497.2416 [M+Na+]. Calcd for C21H38N4NaO6S 497.2410. after which the DMF was removed in vacuo to give an oily residue, which was purified by flash silica gel column chromatography (CH2Cl2/CH3OH, 25/1