All the following refs are for the unsubstituted benzoyl chloride -> benzyl alcohol transformation, but aryl alkyl ethers are stable to borohydrides so the procedures should be just as applicable to 3,4-5-trimethoxybenzoyl chloride:
Reductions with plain sodium borohydride:Reaction Classification: Preparation
Yield: 78 percent
Reagent: NaBH
4Solvent: various solvent(s)
Time: 3 hour(s)
Temperature: 80
oC
Ref. 1: Santaniello, Enzo; Fiecchi, Alberto; Manzocchi, Ada; Ferraboschi, Patrizia; J.Org.Chem.; 48; 18; 1983; 3074-3077.
Reaction Classification: Preparation
Reagent: NaBH
4 dioxane
Ref. 1: Chaikin; Brown; J.Amer.Chem.Soc.; 71; 1949; 122, 124.
Reaction Classification: Preparation
Reagent NaBH
4 dioxane
Ref. 1: Schlessinger; Brown;
Patent US2683721
; 1952.
Reductions using modified sodium borohydride:Reaction Classification: Preparation
Reagent: NaBH
4 AlCl
3 O,O'-dimethyl-diethylene glycol
Ref. 1: Brown; Subba Rao; J.Amer.Chem.Soc.; 78; 1956; 2582, 2587.
With sodium trimethoxyborohydride:Reaction Classification Preparation
Reagent: sodium trimethoxy borate
diethyl ether
Ref. 1: Brown; Mead; J.Amer.Chem.Soc.; 75; 1953; 6263.
Sodium trimethoxyborohydride can be made from sodium hydride and methyl borate as in the equation:
NaH + B(OCH3)3 -> NaBH(OCH3)3And finally with LAH/SiO2 in quantitative yield: Reaction Classification: Preparation
Yield: 100 percent
Reagent: LiAlH
4/SiO
2Solvent: hexane
Time: 3 hour(s)
Temperature: 25
oC
Ref. 1: Kamitori, Yasuhiro; Hojo, Masaru; Masuda, Ryoichi; Izumi, Tatsuo.; Inoue, Tatsuro; Synthesis; 5; 1983; 387-388.
Edit: On page 3 of the linked patent there is some nice information:
The hydrogenation of benzoyl chlorideIn a 1-liter round-bottom flask fitted with a condenser, stirrer and dropping funnel is placed 200ml of anhydrous ethyl ether and 128g (1.00 mole) of sodium trimethoxyborohydride. To the stirred suspension is added a solution of 70g benzoyl chloride dissolved in anhydrous ethyl ether. A vigorous reaction ensues. The acid chloride should be added to the hydrogenation agent slowly, at such a rate that the ether refluxes gently. After the acid chloride has been added, the mixture is permitted to stand for 1 hour and 200ml water is added. The reaction mixture is then poured into a separatory funnel, the ether layer is separated and dried with calcium hydride. The ether is removed on a steam cone and the benzyl alcohol is obtained by distilation under vacuum. The product yield is 49g., B.P. 93-96
o at 11mm.,
nD25 1.5375. The yield is 90% of the theoretical.
By addition of sodium trimethoxyborohydride (1.00 mole) to benzoyl chloride (1.00 mole) in ether at 0o, benzaldehyde is formed. The benzaldehyde is conveniently recovered as its bisulfite addition compound. It was converted into the phenylhydrazone, M.P. 154-156
o.