2,2-dimethylpentanoic acid

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

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

Procedure: 2,2-dimethyl valeric acid (49.0 g, 377 mmol) was added dropwise over 1 hour with stirring to freshly distilled thionyl chloride (102 g, 860 mmol) that was cooled in a water bath. After stirring for an additional 1/2 hour in a warm water bath, excess thionyl chloride was removed by distillation and the crude acid was then fractionally distilled to give 49.7 g of product that assayed >95% by gas chromatography, bp 45°/10.5 mm (lit. bp 45°/10 mm). was cooled in a water bath excess thionyl chloride was removed by distillation the crude acid was then fractionally distilled

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

Procedure: A 240 ml (285 mmol) portion of a solution of t-butyllithium in pentane (1.18 M) was added dropwise to a solution of 42 ml (290 mmol) of diisopropylamine in 300 ml of dry tetrahydrofuran while it was stirred with -5° bath cooling under argon. A 12.7 ml (135 mmol) portion of 2-methylpropionic acid in 15 ml of dry tetrahydrofuran was then added dropwise to the reaction mixture. A 14.3 ml (140 mmol) portion of n-propyliodide was then added dropwise to the reaction mixture as stirring was continued with ice bath cooling. The resultant mixture was stirred two hours without cooling and then acidified by the slow addition of 10% hydrochloric acid. The resultant mixture was extracted several times with ether and the combined extracts were washed with brine, dried (Na2SO4) and evaporated in vacuo to yield 16.3 g of 2,2-dimethylpentanoic acid, having the following spectral characteristics: nmr (CDCl3)δ0.94 (3H, t, J=8.5 Hz), 1.20 (6H, s), 1.2-1.8 (4H, m) and 11.3 ppm (1H, broad s); ir (CHCl3) 860, 945, 1185, 1240, 1290, 1310, 1370, 1410, 1480, 1700 and 2400-3400 cm-1 (broad). cooling under argon as stirring was continued with ice bath cooling without cooling The resultant mixture was extracted several times with ether the combined extracts were washed with brine dried (Na2SO4) evaporated in vacuo

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 604.45 g (2.3 mol, 1 eq.) portion of PPh3 was dissolved in 724 mL CCl4 in a 2 L three-necked round-bottom flask under N2 to give a hazy solution. A stirbar was added and the flask was fitted with a water-cooled condenser topped with a N2 inlet/outlet, mechanical stirrer and shaft, and an addition funnel. The addition funnel was charged with a solution of ExxonMobil Neoheptanoic Acid Prime (300 g, 2.30 mol uncorrected for purity) in 300 mL CCl4. This material was 94.1% purity with an isomer balance of 43.0% 2,2-dimethylpentanoic acid (DMPA), 37.6% 2-ethyl-2-methylbutanoic acid (EMBA), and 13.5% 2,2,3-trimethylbutanoic acid (TMBA) by GC analysis (using FID detection; uncorrected for response factor). The acid solution was added dropwise at room temperature while stirring over a 1 hour period. No immediate reaction was observed other than a decrease in haziness to give a clear solution. After stirring under N2 for an additional hour at room temperature, the addition funnel was removed and the contents of the flask were heated at reflux (˜80° C.) for 3 h. The formation of a white precipitate was observed upon heating. Subsequently, the mixture was cooled to room temperature and filtered. Solvent was removed from the filtrate using a rotary evaporator. The residue was cooled in a refrigerator for 24 h and subsequently crushed with a spatula and extracted with 800 mL hexane for 2 hours. Solids were removed by filtration and the hexane filtrate depleted of volatiles using a rotary evaporator and high vacuum (at 50° C.) to give 200 g of a crude material containing product, phosphine-containing residues, unreacted acid, and other species (most likely neoheptanoic anhydrides). Fractional distillation of the crude material gave neoheptanoic acid chloride as the first boiling fraction (50° C./2.4×10−2 torr; 57.4 g, 17%); higher boiling fractions contained species assigned as neoheptanoic anhydrides (13C NMR C═O 173.1-173.0 ppm; IR υC═O 1808 and 1741 cm−1) and free acids. Elemental analysis calc. for C17H13ClO: C, 56.57; H, 8.82; Cl, 23.85; O, 10.76. Found: C, 56.64; H, 8.96; Cl, 23.60. 1H NMR (CDCl3, 400 MHz): δ 2.17 (septet, J=6.9 Hz, CHMe2 of TMBA), 1.81 (app. sextet, J=7.3 Hz), 1.64-1.53 (m), and 1.35-1.29 (m) (probably CH2 groups of EMBA and DMPA), 1.28 (s, probably CMe2 of DMPA), 1.21 and 1.20 (2 singlets, probably CMeEt of EMBA and CMe2 of TMBA), 0.94-0.88 (m, CHMe2 of TMBA, CH2Me of EMBA, and CH2Me of DMPA). 13C NMR (CDCl3, 125 MHz): δ 180.53 (C═O of TMBA), 180.11 (C═O of DMPA), 179.75 (C═O of EMBA), 57.23 (CMeEt of EMBA), 56.17 (CMe2 of TMBA), 52.84 (CMe2 of DMPA), 42.55 (CH2 of DMPA), 34.34 (CHMe2 of TMBA), 31.41 (CH2 of EMBA), 25.11 (CMe2 of DMPA), 21.46 (CMe2 of TMBA), 20.38 (CMeEt of EMBA), 17.93 (CH2Me of DMPA), 17.22 (CHMe2 of TMBA), 14.32 (CH2Me of DMPA), 8.58 (CH2Me of EMBA). Isomer ratio (average of C═O and CR2 resonances): 12.6% TMBA, 42.1% EMBA, 45.4% DMPA. IR (NaCl disk): 2970 (s), 2940 (sh), 2877 (sh), 1789 (vs, υC═O), 1698 (m, may be acid υC═O from incidental hydrolysis), 1460 (m), 1387 (w), 1369 (sh), 1194 (w), 1066 (w), 1009 (w), 975 (w), 961 (w), 916 (vs), 888 (m), 864 (m), 804 (vs), 756 (w), 743 (w) cm1. to give a hazy solution A stirbar was added cooled condenser topped with a N2 inlet/outlet, mechanical stirrer The acid solution was added dropwise at room temperature No immediate reaction to give a clear solution After stirring under N2 for an additional hour at room temperature the addition funnel was removed the contents of the flask were heated upon heating Subsequently, the mixture was cooled to room temperature filtered Solvent was removed from the filtrate a rotary evaporator The residue was cooled in a refrigerator for 24 h subsequently crushed with a spatula extracted with 800 mL hexane for 2 hours Solids were removed by filtration a rotary evaporator and high vacuum (at 50° C.) to give 200 g of a crude material Fractional distillation of the crude material

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

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).

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

Procedure: A 240 ml (285 mmol) portion of a solution of t-butyllithium in pentane (1.18 M) was added dropwise to a solution of 42 ml (290 mmol) of diisopropylamine in 300 ml of dry tetrahydrofuran while it was stirred with -5° bath cooling under argon. A 12.7 ml (135 mmol) portion of 2-methylpropionic acid in 15 ml of dry tetrahydrofuran was then added dropwise to the reaction mixture. A 14.3 ml (140 mmol) portion of n-propyliodide was then added dropwise to the reaction mixture as stirring was continued with ice bath cooling. The resultant mixture was stirred two hours without cooling and then acidified by the slow addition of 10% hydrochloric acid. The resultant mixture was extracted several times with ether and the combined extracts were washed with brine, dried (Na2SO4) and evaporated in vacuo to yield 16.3 g of 2,2-dimethylpentanoic acid, having the following spectral characteristics: nmr (CDCl3) δ 0.94 (3H, t, J= 8.5 Hz), 1.20 (6H, s), 1.2-1.8 (4H, m) and 11.3 ppm (1H, broad s); ir (CHCl3) 860, 945, 1185, 1240, 1290, 1310, 1370, 1410, 1480, 1700 and 2400-3400 cm-1 (broad). cooling under argon as stirring was continued with ice bath cooling without cooling The resultant mixture was extracted several times with ether the combined extracts were washed with brine dried (Na2SO4) evaporated in vacuo

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

Procedure: Following the procedure of Example 9, making variations only as required to use 2,2-dimethylpentanoic acid in place of 2,5-dichlorobenzoic acid to react with 6-piperazin-1-yl-pyridazine-3-carboxylic acid (2-cyclopropylethyl)amide, the title compound was obtained as a white solid (61% yield). 1H NMR (300 MHz, CDCl3) δ 8.05, 7.96, 6.98, 3.85-3.72, 3.56, 1.64-1.45, 1.23, 0.96, 0.82-0.62, 0.49-0.45, 0.12-0.07. MS (ES+) m/z 388.2 (M+1).