(2S)-2-amino-N,3,3-trimethylbutanamide

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

Procedure: According to the procedure described in Example 1(b) for the preparation of 3(R)-t-butoxycarbonylamino-N-(2, 2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester, 2(S)-[1-(4′-cyanobiphenyl-4-yl)-1H-pyrrol-3-yl]succinic acid 4-benzyl ester and L-t-leucine N-methylamide (see Malon, P.; Pancoska, P.; Budesinsky, M.; Hlavacek, J.; Pospisek, J.; Blaha, K. Coll. Czech. Chem Commun. 1983, 48, 2844-2861) were coupled with TBTU. Successive flash column chromatography with 0-30% EtOAc/CH2Cl2 and 2-5% MeOH/CH2Cl2 gradient eluants, respectively, and radial chromatography with 0-40% EtOAc/hex gradient eluant furnished in 66% yield 3(S)-[1-(4′-cyanobiphenyl-4-yl)-1H-pyrrol-3-yl]-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester as a crisp foam.

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

Procedure: According to the procedure described in Example 1(b) for the preparation of 3(R)-t-butoxycarbonylamino-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester, 2(S)-[1-(4-fluorophenyl)-1H-pyrrol-3-yl]-succinic acid 4-benzyl ester and L-t-leucine N-methylamide (see Malon, P.; Pancoska, P.; Budesinsky, M.; Hlavacek, J.; Pospisek, J.; Blaha, K. Coll. Czech. Chem Commun. 1983, 48, 2844-2861) were coupled with TBTU. Flash column chromatography with 0-5% MeOH/CH2Cl2 as gradient eluant provided in 82% yield N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)-3(S)-[1-(4-fluorophenyl)-1H-pyrrol-3-yl]succinamic acid benzyl ester as a crisp foam.

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

Procedure: According to Example 1(b) for 3 (R)-t-butyloxycarbonylamino-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester, β-allyl-N-t-butoxycarbonyl-D-aspartate (Belshaw, P.; Mzengeza, S.; Lajoie, G. Syn Commun 1990, 20, 3157-3160; 2.00 g, 7.32 mmol) and L-t-leucine N-methylarnide (Malon, P.; Pancoska, P.; Budesinsky, M.; Hlavacek, J.; Pospisek, J.; Blaha, K. Coll. Czech. Chem Commun. 1983, 48, 2844-2861; 1.05 g, 7.32 mmol) were coupled with TBTU. The resultant yellow oil was routinely used without further purification. Flash column chromatography with 2% MeOH/CH2Cl2 provided 2.44 g (84%) of 3(R)-(t-butoxycarbonylamino)-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid allyl ester as a pale yellow oil. The resultant yellow oil was routinely used without further purification

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-cyclopropyl-6-(isobutylsulfonyl)picolinic acid (Example 351 b) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials. MS (EI): m/e=410.6 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 6-cyclopropylmethoxy-5-(3,3-difluoro-azetidin-1-yl)-pyridine-2-carboxylic acid (Example 69 b) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials, MS (D): m/e=411.4 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-cyclopropyl-6-(pyridin-2-ylmethoxy)-pyridine-2-carboxylic acid (Example 189 b) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials, MS (EI): m/e=397.2 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-cyclopropyl-6-(tetrahydro-pyran-4-ylmethoxy)-pyridine-2-carboxylic acid (which can e.g. be prepared in a similar manner than 5-cyclopropyl-6-(tetrahydro-furan-2-ylmethoxy)-pyridine-2-carboxylic acid (Example 166 b)) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials, MS (EI): m/e=404.3 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 6-(3-chlorophenyl)-2-pyridinecarboxylic acid (CAN 863704-38-5) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials, MS (EI): m/e=360.0 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 6-(3-chlorophenyl)-2-pyridinecarboxylic acid (CAN 863704-38-5) and (2S)-2-amino-N,3,3-trimethyl-butanamide (CAN 89226-12-0) as starting materials, MS (EI): m/e=360.0 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-bromo-6-(tetrahydro-furan-2-ylmethoxy)-pyridine-2-carboxylic acid (Example 166 a) and (2S)-2-amino-N,3,3-trimethyl-butanamide, (CAN 89226-12-0) as starting materials, MS (EI): m/e=428.0 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-cyclopropyl-6-(tetrahydro-furan-2-ylmethoxy)-pyridine-2-carboxylic acid (Example 166 b) and (2S)-2-amino-N,3,3-trimethyl-butanamide, (CAN 89226-12-0) as starting materials, MS (EI): m/e=390.4 [M+H]+.

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

Procedure: The title compound was synthesized in analogy to Example 1, using 5-cyclopropyl-6-cyclopropylmethoxy-pyridine-2-carboxylic acid (Example 42 a) and (2S)-2-amino-N,3,3-trimethyl-butanamide, (CAN 89226-12-0) as starting materials, LC-MS (UV peak area/ESI) 96%, 360.2272 (M+H)+.