2-(dimethylamino)acetaldehyde

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 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal]by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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

Procedure: A mixture of 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal]by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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

Procedure: To a solution of 2-(dimethylamino)acetaldehyde (4.79 g, 38.8 mmol) in methanol (50 ml) and 1,2-dichloroethane (DCE) (25 ml) was added (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-(4-chlorobenzylamino)acetyl)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethyl-3a,4,5,5a,6,7,7a,8,9,10,11,11a,11b,12,13,13a-hexadecahydro-3H-cyclopenta[a]chrysen-2(5bH)-one (15) (5 g, 7.75 mmol) at 000° C. The pH was adjusted to 7 with Et3N. The reaction mixture was stirred at rt for 1 h. Sodium cyanoborohydride (0.487 g, 7.75 mmol) was added and the mixture was stirred overnight. The reaction was diluted with water (40 ml), and extracted with DCM (60 ml×3). The combined organic layer was washed with brine (20 ml), dried over sodium sulfate and filtered to afford crude product (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-((4-chlorobenzyl)(2-(dimethylamino)ethyl)amino)acetyl)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethyl-3a,4,5,5a,6,7,7a,8,9,10,11,11a,11b,12,13,13a-hexadecahydro-3H-cyclopenta[a]chrysen-2(5bH)-one (52) (5 g, 5.89 mmol, 76% yield) as a light yellow solid, which was used in the next step. LC/MS: m/z calculated 678.5. found 679.3 (M+1)+. the mixture was stirred overnight extracted with DCM (60 ml×3) The combined organic layer was washed with brine (20 ml) dried over sodium sulfate filtered

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

Procedure: A mixture of 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal]by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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

Procedure: A mixture of 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal] by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal] by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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

Procedure: To a solution of 2-(dimethylamino)acetaldehyde (4.79 g, 38.8 mmol) in methanol (50 ml) and 1,2-dichloroethane (DCE) (25 ml) was added (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-(4-chlorobenzylamino)acetyl)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethyl-3a,4,5,5a,6,7,7a,8,9,10,11,11a,11b,12,13,13a-hexadecahydro-3H-cyclopenta[a]chrysen-2(5bH)-one (15) (5 g, 7.75 mmol) at 000° C. The pH was adjusted to 7 with Et3N. The reaction mixture was stirred at rt for 1 h. Sodium cyanoborohydride (0.487 g, 7.75 mmol) was added and the mixture was stirred overnight. The reaction was diluted with water (40 ml), and extracted with DCM (60 ml×3). The combined organic layer was washed with brine (20 ml), dried over sodium sulfate and filtered to afford crude product (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(2-((4-chlorobenzyl)(2-(dimethylamino)ethyl)amino)acetyl)-9-hydroxy-1-isopropyl-5a,5b,8,8,11a-pentamethyl-3a,4,5,5a,6,7,7a,8,9,10,11,11a,11b,12,13,13a-hexadecahydro-3H-cyclopenta[a]chrysen-2(5bH)-one (52) (5 g, 5.89 mmol, 76% yield) as a light yellow solid, which was used in the next step. LC/MS: m/z calculated 678.5. found 679.3 (M+1)+. the mixture was stirred overnight extracted with DCM (60 ml×3) The combined organic layer was washed with brine (20 ml) dried over sodium sulfate filtered

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

Procedure: A mixture of 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal]by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo

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

Procedure: A mixture of 1.1 g., (0.005 mole) of 2-(3-aminophenyl)oxazolo[4,5-b]pyridine and 50 ml. of ethanol is reacted with dimethylaminoacetaldehyde [from 0.96 g. (0.006 mole) dimethylaminoacetaldehyde diethylacetal] by gentle heating to complete the intermediate Schiff base formation. The mixture is then cooled and 60 mg., (0.0015 mole) of sodium borohydride is added, and the mixture allowed to stir overnight at room temperature. Water is added, the solvents are removed in vacuo, and the residue is distributed between water and methylene chloride. The organic layer is dried and concentrated in vacuo to give crude 2-[3-(2-dimethylaminoethyl)aminophenyl]oxazolo[4,5-b]pyridine, purified via column chromatography using an alumina column with an ethylacetate-ether mixture (v/v 0-60% ethylacetate) as eluant. A mixture of 1.1 g by gentle heating The mixture is then cooled the solvents are removed in vacuo The organic layer is dried concentrated in vacuo